I have a number of iOS devices that all work fine as a roon endpoint if I want to use them as such except the one I sometimes would like to use which is my iPod touch. I have this next to my bed to listen to meditation apps and podcasts. It’s a late model iPod touch 7th generation with iOS 15.1
It also runs Roon fine, I can use it for example to remote control a Naim Uniti, this works perfectly. The only thing that does not work is playing music in Roon to the iPod itself.
I go to Settings/Audio in roon and then I get no option to select my iPod to play to (see picture “ipod”). The same thing on my iPhone works just fine (see picture “iPhone”). I am not offered the local iPod as a zone to enable, there is just no such entry.
My iPod Touch became useless as a Roon device around the time Roon went to V2.0. Same thing happened with an iPhone SE. Neither of them run a current enough version of iOS to be compatible with Roon.
What iOS do they run , my (7 Year) old iPad Mini is on 12.5.7 and still runs Roon Remote happily . Its old battered and the battery is trashed but it Runs Roon.
I found this so anything younger than 6 gen should work. Mine is a 160Gb Classic , not even iOS