is there any possibility to be signed into work account and school account at the same time on one device? I would like to join an online lecture from my company laptop. I tried to enter lecture as a guest, but it did not work. I also tried that in incognito mode, but the result was the same. Do you have any ideas how to solve this problem?
Yes, you can. That's how we all do it as the multi-account / multi-tenant experience in Teams isn't working right now. You can use the desktop client for one account, the domain-joined account preferably, and InPrivate or Incognito browser session for the other accounts.