So I tried all your solutions but it didn’t fixed it.
I tried another usb wifi dongle but I have the same issue: I can ping the rpi and the access to webpage is ok.
I tried to switch to Lan but a few hours laer I can’t play any source of music. I can reach my server, the music starts but I have no sound on my speakers even if my player is playing. I tried with ipeng9 on iOS and iTunes with AirPlay, same issue (in AirPlay I see the squeezebox)
I tried to switch on hearphones with jack output and I have the same problem. I applied “max USB current” for my USB speakers but it didn’t solved the problem.
If I want to use the squeeze box after a couple hours I must reboot the rpi.
I’m desperate! Help me please 🙂