Referencing this post as I'm having the exact same issue and I didn't see a solution posted for this: R Disconnection Issue
I have tried closing the processes manually via the task manager but I continue to see this infinite loop of an error message saying "R Session Disconnected", giving me a button to reconnect, and then showing the same error again. I've tried uninstalling and reinstalling RStudio. I don't have multiple instances of RStudio and I'm not even using a browser to use it. Out of ideas!