Which version of Ubuntu system did you upgrade? Did you try rebooting your computer? And what's the version of your controller?

@fredriknb Hey, I found your EAP's firmware is not even compatible with your controller, which is V3.3. How did you configure it on the Omada controller? They both have newer versions which are...

@Gabriel_Esp Hey, There are two different kinds of Voice VLAN configurations. If you mixed them, you may lose your configuration after reboot. See this article to check your settings:...

@HomeAdmin No better idea. But Ubuntu 20.04 is not recommended officially. I think you can try to install it with Docker. See this thread.

If you have different VLAN interfaces, did you set switch ACL to block different VLANs? If no, different VLANs should be able to access each other by default. And what's the management VLAN for?...

Does deleting the file one time resolve this issue completely? Seems the controller just shut down abnormally. I ever run a controller on Linux system, but I didn't have this issue.