MacBook Pro self assigned IP, no WiFi, no cabled connection possible

This morning I found my MacBook Pro (OSX12.4) without a WiFi-connection. All the other Apple stuff is running smoothly. In the network settings I see ‘WiFi has the self-assigned IP-address ….’. I understand this is one of the first steps in connecting to the router. In my Deco mesh network, I do see the MacBook Pro, not in my router. When I try to connect to the WiFi of the router directly, nothing happens. Wired connections aren’t working.

I have spent hours to solve.

• I have deleted files in /Library/Preferences
• I have deleted the WiFi entries in the keyring
• I have rebooted the router, the mesh network, the MacBook several times
• I recently had an issue with McAfee and removed it from the MacBook

I consider to reinstall the machine as new, but before doing that I hope to get a clue from someone to get it fixed somewhat quicker.

The strange thing is that Some mail has arrived during the night, and apparently that was the last internet activity for the machine….

I’m looking forward for suggestions!

Thanks Edward