I have read the other posts in the thread so somewhat understand the things you already tried. I also went through the Diagnostic Logs - I dont see anything which can help us since the first thing UiPathStudio.exe or Robot.exe do is look for orchestrator and check license.
My analysis is that this is issue realted to multiple versions trying to connect to different folder (Classic and modern) types in the tenant in Orchestrator.
Could you try this?
Since I see you installed the latest version of UiPath Studio 20.10.2 from the logs, I would request you to ditch the classic folder and only use modern folders in Orchestrator. Why? It is because in a modern folder all you have to provide users, which machine they are using and what license they are allowed. (If using unattended provide the windows password)
Then you can create a machine template instead of individual machines. Copy the machine key of the machine template and use the robot.exe -connect command as you said before:
UiRobot.exe --connect -url <YOUR_ORCHESTRATOR_URL> -key 072c0bfe-c4b5-****
The other advantage with the modern folder is that you dont worry about provisioning robots or studio/studio pro. A user itself can be given these and every user has a machine (when creating users).