I had to factory reset, adopt and reconfigure it.

Things like this MUST NOT HAPPEN on enterprise level products!

  @GaRv3 

Thank you for your post. There can be many reasons why a switch disconnects. When it goes offline, can you run a ping test to verify connectivity between the switch and the Controller? In addition to resetting and re-adopting the switch to restore it, does simply rebooting the switch bring it back online when it disconnects?

You should also check the Controller for any logs that might indicate why the disconnection occurred. Furthermore, is this disconnection happening frequently, or is it only an occasional issue? If it’s frequent, roughly how often does it occur? When the problem arises, is the traffic on the devices connected to this switch still normal?

The next time this happens, after rebooting the switch to restore connectivity, please export the device-info file for us so we can perform an initial analysis.

  @Ethan-TP 

This happened once - presumably after a power outage. The logs just said that it disconnected.

Rebooting the switch did not help. This was - of course - one of the first things I tried.

I did actually download the device info. Can I post it here or does it contain any private information and should be sent via PM?