As you are facing trouble with Gmail IMAP Accounts in Outlook 365, it is because of not proper sync of emails. You can make use of the software that can help you in moving the Gmail IMAP account email in Outlook 365 easily and safely. Download Softaken IMAP Migration Tool for this process to move all the Gmail to Outlook 365 through IMAP server. It will simply sync all your email properly in Outlook 365 without lossing any bit of data.