Hi Juan,
Please follow the steps below to perform the activity to find the POP settings for your Office 365 account.
1. Please log in to the OWA through http://mail.office365.com/ with your account. If an error shows up saying wrong user name and password, please contact your organization administrator.
2. Click 
> Options.
3. Click my account under account tab.
4. Click Settings for POP or IMAP access… and find the detailed settings for POP.
5. Type the settings into your Gmail and check whether the issue still exists or not.
I did a test on my account base on the steps I provided and it works. So please let me know the result, then I can do further troubleshooting.
Thanks,
Yang Yu