There is a bug with the Google Business Profile agency dashboard where owners and managers cannot accept new invites. The issue started a few days ago, Google is aware of the bug and working on fixing the issue.
Ben Fisher posted on X saying, “Agency Dashboards not able to accept invitations.” He added that
this is a new known issue” and that he is working working with Google to resolve it now.
Here is one screenshot of the issue:
Ben said you should go to the forums and show screenshots of a profile that invited you (the users area), and post your ORG ID as well, so that Google can debug the issue.
There is no ETA for when this issue will be fixed.