Interesting, my firewall blocked the update process of MS Edge. So I had 87.0.664.66 in use. I corrected this and updated to the version 89.0.774.48. After that I tried two times to copy text into the textbox of a public message. The first time it worked, but not the second time. I kept trying and found out it has something to do with the loading state of the game. If the game has been not loaded completely, to insert text in the field with CTRL+C is possible, but not anymore, if the remote project has been loaded completely and is playable.