MicrosoftKathy Liu Nope. There is no "Me" control or any other way to log out when completing the form. See screenshot below.
I have gone around and around with Microsoft support on this issue and the conclusion was that this is by design because you do not support shared devices or kiosk scenarios, which doesn't seem very acceptable.
Even if you navigate to another O365 page such as just going to office.com and clicking the "me" control and logging out, it does not log you out of Forms. You can log into Office as another user, go to the form, and you are still logged in as the prior user who thought they logged out. You can even see their form submission data, which seems like a huge data security hole.
I am happy to provide more substantiating information. This is 100% reproducible, and has been a problem with Forms for years that I would love to see fixed.
Screenshot with no logout option:
