The Gmail client is not recommended for use with UiOs MS365 hosted email. We recommend Microsoft Outlook in order to avoid calendar synch issues and room booking issues.
Look here for guides on how to get Outlook and set it up, see here: /english/services/it/email-calendar/outlook-mobile/help/
To set up MS365 mail (cloud hosted) on a personal device:
Open Gmail app, if you dont have any mail accounts set up, discard the welcome message, and Add email address .
If yo have a personal email account already, tap the icon to the right in the search field, and choose Add another account.
Choose Exchange and Office 365 from the list of services.
Insert you email address, and tap continue.
Authenticate as the device prompts you for (2FA), and you are done.