I have a client with the exact same issue. I am a Mac user too. I use Teams on both of my Macs. I keep macOS up to date, and Teams is always up to date as well. I run macOS Monterey on both Macs. When I click to join a meeting in Teams, it opens up in Teams every time. What happens with my client is that when he clicks to join the meeting, Safari opens. Microsoft has not yet made it possible for Safari to work with Teams, but that is irrelevant since we're not trying to open the Teams meeting with Safari. If I change the default browser to Chrome, this provides a workaround that allows him to join the meeting since Chrome gives him the option to open the meeting in Teams. As far as I can see, this appears to be caused by some kind of default setting for what app should handle a Teams link. I can't find anywhere to find this setting and change it. Yesterday, I used the Teams reset tool provided here: https://office-reset.com/macadmins/ After running it, we had to login to Teams again. It had no effect. My next thing to try is to use an uninstaller app called AppCleaner to completely purge all traces of Teams from his Mac, and then check if he can open meetings and join them from within the Teams app. As I mentioned above, it seems that Safari is set as the default app to open Teams meetings. I believe this is the root cause of the problem, but I have so far not found a way to change that setting. It would be super if someone from Microsoft would respond and give some advice on this. I am frequently disappointed at how Microsoft handles issues with their software on Macs. There's a well known issue with Skype that has been going on for at least 7 years that they have never actually addressed.