My workplace switched from Slack to Teams a year ago and it was a complete disaster. In addition to numerous flaws that would be repeated by others, some users including me couldn't sign in with cooperate accounts at all---every time I put the email address it skips passwords and always ends up with a clueless generic error message with a non-functional "retry" button.

I have since found a workaround which requires reinstallation per each launch, because the installer installs an older version that will soon be automatically updated to a newer version, and that older version can retry on the failure with an alternative login prompt that actually works. So Microsoft has at least two login prompts, only one of which is working for me but unsupported by some versions of Teams so that I can barely work around. Brilliant.