Don’t worry about the grouped issue, your situation can be fixed by going to tvOS 13.2 beta. You could also just wait until Apple releases the stable 13.2 version.
You can (temporarily) join the Apple beta for the tvOS 13.2. That’s what I did.
Edit: It looks like you need to enroll in the beta program on Apple’s website first in order to participate. I did so a while back and forgot the procedure.
On the Apple TV, go to Settings > System > Software Updates. Click Get Beta Updates to On. Then click Update Software.
It should update you to tvOS 13.2. You can the go back to Get Beta Updates and set it to Off again.
Just an FYI, my (US) TVOS is on 13.0, is deemed by Apple to be up to date, and does not offer a beta OS version (to be exact, no line that says " Set Beta Updates to ON").
Thanks for all this, I kind of assumed it was an update as non-Apple outputs still working fine. Have done 13.2 on HD and it’s fine. Presumably it’ll be good on the previous one (the last one with an optical out, annoyingly!). But I’m turning off Beta updates again afterwards (or will turn off automatic updates maybe), or I might get a(nother) dud one without knowing.
I’ll let 4k do itself when the full release comes out.
Waste of a couple of hours I really could have done without today!
And I find Apple TV fine by the way for non-critical applications like my workroom and dead cheap compared to ‘proper’ bits of kit. Ebay ones even cheaper.
Thanks for the clarification. I will be using native Tidal app on Apple TV until iOS 13.2 is released, seems more reliable than the other workaround I posted above