MAC MINI DP Display does not wake up after sleep

As lengthy described i.E. here:

https://forums.macrumors.com/threads/2018-mac-mini-static-after-sleep-awakening.2161504/

When a Mac Mini ( in this case late 2012 ) stays awake and the connected screens went asleep, they do not (always) wake up again:

The HDMI screen always comes back to work.

The HDMI screen wakes up but shows "no input".

The Mac trusts, there is a DP screen connected, but no Picture.

The only "repair" many people (including myself) found was a cold start of the mac!!!

Nothing else ( Switching off/on screen / changing cables / changing screens and so on ) worked!

I cannot believe, that a cold start is the only option to bring the picture back. Looks like a crashed part of the display driver, but, a restart should be possible.

Many people describe exactly the same problem without solution!

And, people also write, that using Windows with boot camp on the mac works without any problem.

As the problem seems to be there for many different screens, cables for me it is a software problem on the OSX side.

---> PLEASE, can anyone give a hint about the "magic" command to reset only the DP video without a cold start of the whole computer???????