Roon is almost constantly sending and receiving data, but not in continuous streams (caveat: as I understand it, in other words resist the temptation to be led by the witless). So it could be this that is causing problems on the laggy connection in your new place and tripping up the router.
Setting up a Roon Core on a Mac/PC and seeing what happens might therefore allow you to rule it out as a problem with the Nucleus.
Hi Mike…I have had my Hub for four months. It is a Home Hub 4 Type A. Our phone line comes directly from the exchange, not from a green box in the road. Which is why our speed is only 6 mbps!
I understand that if we were in a normal road, the speed would be about 35-45 mbps, which would require a different Hub. Or so I’m told?
Although it is slow, it’s been rock solid for four months. I have not changed anything in the system.
Just downloading the free trial to my iMac…I’ll let you know 
Update: Within 20 minutes, the Roon Core on my iMac (Wi-Fi) has knocked out the Hub!
Hi again DJM.
OK if it’s rock solid, then yes leave alone.
But I would still like to ask BT why you’re so limited & what’s the plan for your area to get linked to the fibre system, 6mbs is well below BT’s superfast commitment.
Your HH4 will still work on a FTTC (green box street cabinet) but if you changed your contract to one of the new BT ‘Halo’ contracts, then you would get a Smarthub-2, & a choice of either (aprx) 35mbs or 74mbs
BT did explain originally, that because I have an ‘Exchange Line’ the speed would be 3-6 mbps! We are renting on a farm, in the middle of nowhere! (Cambridgeshire) 
Thank God we are moving! I checked the broadband 35-45mbps.
Just sent an update to @Michaelb. The plot thickens!
Well, then, I think that tells you it is the way Roon is using your broadband connection that upsets the modem/router rather than a problem with your Roon Nucleus.
So it appears as if your options are either to not use Roon until you have completed your move or to try a 4G or 5G connection. Do you know what the mobile signal is like at your current address? BT may be able to help here… or you could perhaps use your existing mobile contract with tethering (connecting the Nucleus to your Mac and connecting the Mac (via Wi-Fi) to your mobile network. I’ve never tried the latter but it might work…
Is all your music stored on the Nucleus?
Hi Michael…Yes, most music stored on Nucleus, but a couple of dozen of artists on the iMac.
When my NDX2 arrives, I think I can get it to stream the files from my iMac?
Is it possible to use the USB on the Nucleus, and put Wi-fi dongle on?
I’m pretty sure that won’t work. Better to put a wireless access point on its Ethernet port.
Yes, just give Roon access to the music folder on your Mac and it will integrate it into its library.
That is very helpful, thank you.
I have heard of the term, “Wireless Access Point”, but had no interest as it wasn’t required. Any tips or brand?
In the past I’ve used an Apple Airport Express for such purposes, and they are available very cheaply on the used market now. However, it’s rather dated gear now, and it works best in an all-Apple network.
What networing equipment are you using now? The best choice might depend on what you already have in terms of compatibility and ease of use.
Edit - I see you have a BT router - the BT WiFi discs have a good reputation as wireless extenders so that’s what I’d look at first, although I don’t know about compatibility with older routers.
The BT white coloured discs work with the older HH hubs.
The black discs are purpose made for & only work with the Smarthub-2.
If a house move that includes an Openreach fibre service is planned, I would hold out for that & go with the Smarthub-2, & an extender only if needed.
But how does this fit in with the Nucleus?
Many wireless access points have a LAN port which allows you to connect devices via an Ethernet cable. The connection from there back to your router can then be either wired or wireless, the former being preferable where possible. I’m assuming this is what you wanted to achieve when you mentioned using a “WiFi dongle”.
I was thinking that the dongle could connect in the USB on the Nucleus, creating a Wi-fi connection. But I realise now that can’t be done.
Thanks for your help.
Hi, I saw my name pop up… so responding to see if I can help.
In short I see that your nucleus when connected via Ethernet to your HH4 it’s causing the HH4 to reboot?
That is indeed perculiar… and I suspect we are dealing with a fault somewhere…rather than an interoperability issue.
I see there is mention of using wifi instead of Ethernet… I’d possible with the nucleus it worth a try…but on,y if wifi directly built into the nucleus.
However I would be inclined to get to the bottom of the Ethernet issue.
One thing to try is to put a small cheap switch between your HH switch port and the nucleus… does that stop the router rebooting?
Do other loads on the home hub cause Ito reboot, ie streaming Netflix or downloading a big file?(via ethernet, not wifi). If this is also causes a rebooting issue, time to replace the HH.
Obvious things to also try to rule out certain physical defects try different router switch ports (you have four to choose) and try different ethernet leads.
Let me know on the above… in short.
As said above the HH4 is old, and it’s heatsinking become less effective, but no clear evidence that is the cause from what I can see.
Edit I think you say you have tried wifi, and the issue still occurs…
If so I would shift focus, your house internet connection and your router
Is it VDSL? (Ie superfast) Go into the advanced setting on the router and see what noise margin you are operating.
You should 3.3dB or less on the downlink. If you are seeing higher, or the noise margin is moving about each time you refresh the screen, you may have a faulty internet connection line to your house, or less likely a source of significant RFI in your house or near the cables between your house and the green cabinet… these can include faulty street lamp, and faulty farm electric fences… but this would affect many people typically.
A good baseline check is to also use to see if there might be a connection or interference fault is to use
https://www.broadbandchecker.btwholesale.com/#/ADSL
How does your router sync speed compare to the values shown. (Note this is on router info and diagnostic screen, and separate from so called third party ‘speed’ tests.)
Do the expected sync speeds
At this point there are things to do with a silent line test (dial 17070 on an analogue phone) etc…and a remote line test that you can initiate via your BT account portal.
I know it seems complicated but one needs to narrow down… it’s a bit like in a car saying one hears a noise at a certain speed, or one hears distortion on vinyl in the inner grooves… it can be many things and is a process of elimination.
Thank you Simon for your kind help. I will answer your questions the best I can.
The Roon Nucleus is Ethernet only. A community member suggested a Wireless Access Point.
I have been using a TP-Link 8 port Switch when the fault first occurred. I removed the Switch incase it was faulty, and connected the Nucleus directly to the Hub. Dropouts/reboots still occurred every 15 minutes.
I have three other devices on the network. Smart TV, Manhattan Smart PVR, Bose Soundbar. All rock solid with Ethernet and Wi-Fi.
The BT Hub is a HH 4, Type A. It was replaced a week ago. Still the same issue.
The reason that BT supplied this type of Hub, is because we have an ‘Exchange Line’ which comes over land, directly from the exchange, not a green box in the road. Hence our top speed is 6 mbps max! 
I have accessed the Hub Advanced Settings, no sign of VDSL.
I obtained the attached screenshot, from the link you gave me. Means nothing to me! 
I’m carrying out a test: I have downloaded a free 14 day trial version of Roon, and stuck it on my iMac. The iMac is connected by Wi-Fi. So far, I have had one dropout/reboot in the space of 75 mins.
I’m sure I’ve probably forgotten something, but please just ask again.
Once again, thanks for your help.
A quick update:
11:53 Nucleus connected directly to Hub by new Ethernet cable (AudioQuest Cinnamon 0.75m cable).
12:08 Dropout/Hub Reboot
12:24 Dropout/Hub Reboot
12:40 Dropout/Hub Reboot
12:57 Dropout/Hub Reboot
You can almost set your watch by it.
ok you have had a new hub - your stats show you’re ADSL, not VDSL - which corresponds to your comment about exchange line which would be correct - and your speed is quite healthy for ADSL, although we don’t know your current sync speed - perhaps you can share?
The fact the reset is every 15 minutes (ie ie you can set your watch buy it suggests this is some device or automation causing this) - can you advise if the router itself resets or just the ADSL connection. The logs should show on the admin connection - another way - do internal connections remain active through the HH when it ‘resets’ or do they drop as well.
Ultimately if you have had a new hub - and connected direct your maintenance port (remove the font of your phone/DSL socket - loads of hints on the web about this ) - this way you isolate home wiring and some home interference issues - and it still happens - and other loads like downloading files or streaming video causes no issue - then I am afraid it looks like you have a faulty nucleus
Except that the same thing happens when the Roon Core is on the iMac……
Sure, have you checked the other aspects I suggested… does the HH actually reset… or is it he ADSL resyncing? And does the resyncing occur with other loads such as streaming Netflix or similar (ie same sort of load as Nucleuus)
