This has been such a problem that, going to a significant scientific conference that was online during the pandemic, and had organizers who insisted on using Teams, the organizers asked everyone to provide a personal email address in addition to their academic one, because they had had too many problems in the past with people being unable to log in to their Teams system if their email address was associated with another university's Office 365 system.

They proceeded to primarily use Teams as a chatroom to let people know when the Zoom meetings were starting.