Additional features, settings, or issues not covered by specific Microsoft Teams categories
I have the same issue. I am on a MacBook Pro, running Teams desktop app. I can't tell you what version because the "About Microsoft Teams" doesn't work. Your developers should be reprimanded for poor work. But I believe it to be the current version.
I am writing this on the same laptop. Clearly I don't have a network issue. The firewall is OFF, and has been off the whole time. I have NO connectivity issues with anything else. The app used to work until a recent "upgrade". The text says to try "signing out" and back in. The link does not work. The Restart button does, sort of, but it doesn't solve the problem.
And yes, I can access Teams via a web browser (Edge).