Playing Apple Music and casted to iPhone for control. Volume display remained visible despite changes in menu, turning screen off then on, including powering off. Only a reboot cleared the screen.
That has happened to me too. What are you using to change the volume? If you are using the remote, make sure the antennas are up straight. Also make sure your internet is optimized. I have had great troubles on a wireless connection with AirPlay with the volume jumping all over the place. But the connection with the remote is supposed to bluetooth but it also happens with using the volume control manual too so the internet must be involved. Apple Music is much more stable but it has happened just like you. Now that I have ethernet AM is much better but AirPlay 1 still needs work even after downloading the new beta software.
I do not have a remote so I am using my iPhone (cast from DMP-6) to control Apple Music. If I had a guess, I would say it is somehow connected with the iPhone going into auto-lock. If this is the case, the display is sometimes frozen and I need to exit and re-enter the cast mode. The Eversolo is wired to router, so WiFi is not operational.
Another thing that may help is rebooting your phone too while the A-6 is on so the phone can find the signal again.
Reboot of A-6 resolved the issue but if I see it again, I can power off/on the iPhone and see what happens.
