RPA Bot status "Waiting for Robot"

I have a problem with Microfocus RPA 2020.11 Trial version.
Everything was working fine until at some point processes stopped running because they go from "In Progress" status to "Waiting for Robot"
The robot service is running and there are no other running tasks.

At this point, every run ends with the task status stopping at "Waiting for robot" status after a few seconds

Restarting the machine does not help.

What could be the problem here?
Can reinstalling the robot help here? If so, how to do it in Trial version.

A screenshot is attached.

Regards

Łukasz