This user has been able to use the IMAP connection to receive all his emails from Gmail into outlook with no problems. He had to change his Gmail password, and then Outlook asked for the new password. While entering the password the text in the password box seemed higher than usual. After entering his new password the next screen you must click on ALLOW, only the ALLOW button is grayed out. So far the only fix I can do is to reinstall Windows and Office again completely.
Microsoft® Outlook® for Microsoft 365 MSO (Version 2304 Build 16.0.16327.20200) 64-bit
I have found this was fixed, but its not and the workarounds don't work.
I have this same issue and have tried every solution I could find, nothing works. I also have )365 version. Scrubbed machine, bumped it to Windows11, fresh install of Office 365. Outlook appears to pop up a browser window that the buttons won't turn on. I turned off the IE 11 options, but no joy. Wired part is - if I say I want to try the "New Pre-Release" version of Outlook, I can add my GMAIL accounts. Something hinky about this build!