Saying this without any knowledge of the actual architecture of Naim products, firmware is not just software in the sense of something you install and run. It’s the code that is embedded in hardware processors telling the processors what to do. Not everything is hard wired.
That is how you can add support for a new file format to a decoder, for example, without replacing the physical chip.
So it could very much affect SQ.
I was been contacted by Naim technical service (thank you, @Richard.Dane ), initially asking me for system configuration details, and subsequently to tell me that “they had reports that logging out of Tidal corrects the issues”, 
Unfortunately, as I have replied them, in my system, the firmware update main novelty, which I was looking forward to, does not work in any sense: Tidal playlists, albums and tracks appear in ‘Favorites’ both in the App and in the device screen, and initially it is possible to select them as ‘Presets’, but after a few seconds (it doesn’t reach a minute) mysteriously disappear, dropping off from the ‘Prests’, both in the App Presets screen and the NDX2 Favorites screen.
So, I hope for a solution as soon as possible, as it would be very unfortunate to have to wait until a next update… Although I think it isn’t going to be…
Greetings to the forum.
I haven’t read all 200+ posts here, my first Star update worked just fine. However, I noticed I wasn’t given an option to refuse the update. If I continued to open the app, I was only shown the Setup screen. If that’s the Naim strategy, they better make damn sure the firmware upgrade works fine. judging by some of the posts I see, that’s nnot the case everywhere.
Yes, I’m experiencing a similar audio change on my ND5XS2, but then recently I’ve felt Qobuz was lacking in detail and I thought it was my ageing ears. More detail has returned.
One thing I have noticed since this firmware update is that my ND5XS2 no longer has a relay click from inside ,when I switch it in and out of standby from app or front panel power button. I only hear a relay click now,when the mains is turned off or on at wall socket.
That’s probably because it has defaulted to having server mode switched on, check the settings and see
I had this exact issue @newcomer. I resolved it by logging out of, and back into, Tidal through the App.
Naim haven’t been able to answer my question about favourites from the Uniti Core not being able to be set as presets, or be visual through the tree-structure on the screen via the remote > home > favourites route that works with all Tidal favourites (even if they are nor presets), but it seems you need to have one preset set up for this functionality to work). Maybe @Richard.Dane may be able to get the software guru to pop into the thread with a clarification on that? Or one of the beta testers could explain what the functionality should be?
Error Code 311, what does that mean?
I have had my Naim-system turned off for approximately two weeks.
This evening it was finally time to start up the system again fore some music listening.
My ND555 seems to start up as usual in the beginning. After some time “updating” shows up on the display. I guess that the new SW will be downloaded… However, after a few seconds, the display instead shows the message “Error Code 311” and nothing more happens.
I would guess that there are something wrong with the SW download to my streamer? Have anyone else seen this and how do I get my streamer to work again?
I will contact my dealer tomorrow but I was wondering if I could get faster information here on the well-informed forum
/Marcus
I’ve always been wary of the fact that software/firmware updates change SQ. When I owned an NDS I was very thankful for the fact that I was able to revert to the 4.4 software version as I found 4.6 had destroyed the involvement of my Streaming experience. The latest systems don’t seem to offer any choice: a change is permanent and you like it or lump it. I’m uncomfortable with that quite honestly…
I’ve updated the firmware on my ND555, but haven’t listened to it for 2 weeks. Nothing to do with e update I hastily add, simply that I’ve only been listening to vinyl following the Karousel, Sara, Urika, Krystal upgrade. 
Not wanting to put the kiss of death on the firmware update but it has improved the functionality of the app in terms of responsiveness. I guess that my ears aren’t “golden” enough to hear sound quality differences. I hope that someone can explain how a firmware update can improve sound quality to me, assuming they are using CD or a usb stick for sound input?
I got it to work by power down and disconnect the two Burndy cables from the back of the ND555 for a few minutes. Just to feed back some info if somebody else get the same problem…
I have the same Core ‘preset’ behavior. Nothing on the Core can be set as a preset (not that big of an issue). I can set as a ‘favorite’.
Otherwise the firmware updates for my Core and NDX2 were without issue. I really appreciate that the Core now supports larger drives and the exFat file format as well as Mac OS file format support for large drive back-ups.
I have been fortunate - I have not experienced the NDX2 screen issues that many have lived with.
Marty
After updating my NDX2, the front panel no longer displays the album art briefly at the start of playback (“Turn off during playback” set to true), except for the initial track. After this, no matter what subsequent album or track is selected, it does not display the album art at all as it used to prior to the update. I see this behaviour whether via the Naim app or Roon. Anyone else experience this or am I losing it?
The Naim support chap couldn’t advise on whether that functionality should work with the Core. He must be working from home, because he said he didn’t have a Core to be able to check it. All rather odd that Naim support don’t know how it should work.
I can quite relate to that!
Worrying that my LP12 with an ancient Cirkus bearing and past it cartridge was still more involving than I’ve ever found digital sources to be.
Same issue here
Support recommended to log out of Tidal and power down and restart the app.
to remedy my woes. I had already said I don’t use Tidal via Naim as I use Roon and had done a powercylce and the app has been closed and restarted many times. Not exactly stellar support. I am away from home until later so will try a factory reset. Why I should have to do this every time there is an update to make it work or sound correct is beyond me.
Not really first line support on the whole are mainly triage and basic level support, they get you to restart stuff etc and check connections they are not engineering level, you only get the main bods after escalation with some knowledge as a big chunk are solved at this stage with these simple things.
I noticed my Uniti Star seemed warm during standby. I performed a factory reset and answered the question about server mode with “No”, but it was still warm in standby (7-10C over ambient). I then went in the App and could see server mode was not ticked but ticked it then unticked it. Now the unit is cold in standby! Looks like a bug that needs the setting set then unset to make it actually work correctly.
Otherwise the 3.5 update has been good for me, so far.
I have updated to 3.5 a few days ago and have now looked at my the app and Server Mode (for my ND555) is ticked. I use either a UnitiServe or a QNAP NAS to server music.
Did Customer Service say Server Mode should be unticked?