I’ve bought a secondhand Mu-so 2.
The serial number: 1702030165
System Version: 4.4.0 (6575)
App Version: 7.1.1 (11754) iOS
I purchased this as a second-hand item. Unfortunately, the Chromecast built-in does not work. The speaker can not be discovered by any devices.
I tried to uninstall/install the app and factory reset the speaker a lot of times, but it did not work.
There may be an issue with Google Chromecast Token. Everytime time I tried to add the speaker to my app, at the very last step, there was a pop-up saying that I cannot use Chromecast (see attached).
I also try to turn on the Chromecast built-in in the Input setting but it will automatically be turned off right away. There are no times that the speaker is discovered by any devices.
If you bought it from a Naim dealer, then talk to them.
Otherwise you need to raise a ticket with Naim themselves.
Chromecast uses a unique google token which is generated and stored within each device. It is theoretically possible for this process not to succeed, but Naim have the ability to correct it.
Your serial number starts with 17 indicating a 2020 build year.