Ubuntu 20.04 LTS lan network problem

This is the error logenter image description hereI have duel boot desktop system Window and Ubuntu. I deleted Ubuntu 18.04 LTS which was working fine and installed (not upgraded) to Ubuntu 20.04 LTS. Everything was fine but later I got several problems. I loose the lan network connect every night. when I go to the office I close the network connection and start it and it works fine for several hours and something still works for days. In the beginning the network always showed a question mark on it. Now it does not show anything and internet connection drops.
I installed caffeine so that the pc does not go to sleep and I removed the screen server in the power section.

I am not sure if anybody has this problem with Ubuntu 20.04.

I also have a problem with teamviwer with this Ubuntu. Every time I switch off the display I can not longer use teamviwer.