I can conect to my Macbook laptop from my ubuntu desktop in the lab via teamviewer. Unfortunately, attempt to connect to this same desktop from the macbook is aborted, with the message You are blocklisted or not allowlisted by this partner. Apparently, the ubuntu desktop rejects any connection. I can confirm from with teamviewer on ubuntu desktop no user is added to blocklist:
Uninstalling teamviewer and reinstall didn't help.