CRM Email & Activities - Outlook account marked as "Not active"

Hi all,
On the CRM module Email and Activities, our Account Managers have their Office365 Outlook mailbox integrated with Monday and it works fine for several weeks, but without any apparent reason the user mailbox are marked as “Not active” and the emails stop appearing on Monday, this happens recurrently with a lot of users, not all, although the users didn’t change the password and Outlook is working perfectly.
Any ideas why? Is there a period of inactivity of integrated email that fires this “Not active” state? If this period exists is there any place where we can configure it?
Thanks for all the help!