iPhone Outlook won't download emails.

There are several boxes on Gmail, one main with a lot of letters. Outlook on iPhone cannot download letters from the main mailbox, loads a certain amount and stops, new ones do not come either. Works fine with other boxes. Tried to connect via Google authentication, tried to connect via IMAP, nothing helps. Tried on iPad, same thing. Resetting/reinstalling the app didn't help either. If you install the Gmail application or any other mail client, there are no problems with this mailbox.