After upgrading my M1 mbpro to macOS 12.4, my Dell U4021QW not connecting via Thunderbolt.

I narrowed the problem down to leaving the M1 macbook pro with lid open, going to sleep and waking up after a while -> No thunderbolt, no charge from magsafe. 

The solution was to run

sudo pmset restoredefaults

And shutdown/start after that. The issue is not repeating then.

The problem should be rooted with myself changing some of the pmset settings after buying the macbook. The M1 macbook was not sleeping at all as it seemed and I was trying to fight it with pmset settings. Now, with macOS 12.4 it just fired back with something that Apple has not tested for the specific overrides.

Hope this can help to someone.

To answer myself.

After a while I noticed that actually Macbook is not charging at all (even via magsafe) or is not reacting to any thunderbolt input/output. I tried to shut down and it restarted instead. I shut it down again and this time after coming back, thunderbolt started to work, including connection and charging with Dell U4021QW.

TLDR; After macOS 12.4 upgrade, if you have a problem with thunderbolt, try shutting down the mac until it really shuts down and after that thunderbolt issue might fix itself (fingers crossed).