I have a similar issue - may be related. I sometimes experience, that Volumio 3 on a RPi 3 just hangs (UI is not reachable via Browser). When I log into it using SSH and issue a journalctl -f, I see a “Successful connection” message every 15 seconds, but nothing else happens (UI not reachable). Sometimes, it just stopped after some minutes - today it is persistent.
I can sometimes make it go away, by issuing a volumio vrestart but today, that does not help.
Today, the restart makes the UI reachable again for a short time, but then, it hangs again with the same symptom.
Below I captured the last appearance from the point where I connect via Safari from my Mac to the point where it starts to hang. Hope it helps to get an idea.
Yesterday, the same system worked just fine for the whole evening.
(while I wrote this message, the final line kept repeating for more than 10 minutes, with an interval of 15s.
Feb 07 20:41:53 volumio volumio[22047]: verbose: New Socket.io Connection to 192.168.178.64 from 192.168.178.23 UA: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.1 Safari/605.1.15 Total Clients: 4
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: my_volumio , getMyVolumioStatus
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: multiroom , getMultiroom
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::volumioGetState
Feb 07 20:41:53 volumio volumio[22047]: info: CorePlayQueue::getTrack 1
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::volumioGetVisibleSources
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: my_music , getDisabledSources
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: appearance , getUiSettings
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: wizard , getShowWizard
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: system , getShowWizard
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: system , getPrivacySettings
Feb 07 20:41:53 volumio volumio[22047]: info: CoreCommandRouter::executeOnPlugin: my_volumio , getMyVolumioToken
Feb 07 20:43:06 volumio volumio-remote-updater[475]: [2022-02-07 20:43:06] [disconnect] Disconnect close local:[1008,Pong timeout] remote:[1006]
Feb 07 20:43:11 volumio volumio-remote-updater[475]: [2022-02-07 20:43:11] [connect] Successful connection
Feb 07 20:43:24 volumio volumio-remote-updater[475]: [2022-02-07 20:43:24] [connect] Successful connection
Feb 07 20:43:39 volumio volumio-remote-updater[475]: [2022-02-07 20:43:39] [connect] Successful connection
Feb 07 20:43:54 volumio volumio-remote-updater[475]: [2022-02-07 20:43:54] [connect] Successful connection
Feb 07 20:44:09 volumio volumio-remote-updater[475]: [2022-02-07 20:44:09] [connect] Successful connection
Feb 07 20:44:24 volumio volumio-remote-updater[475]: [2022-02-07 20:44:24] [connect] Successful connection
Feb 07 20:44:39 volumio volumio-remote-updater[475]: [2022-02-07 20:44:39] [connect] Successful connection
Feb 07 20:44:54 volumio volumio-remote-updater[475]: [2022-02-07 20:44:54] [connect] Successful connection