Cant See outbox items on a secondary Account

Hi I have Microsoft 365 Outlook via my pc used to be on an exchange server but now via a networked pc. My main email address works fine. My problem is I have a colleagues email address account set up on my pc. I can see inbox, sent, and junk perfectly well, I have the Outbox showing but when I go in to it it says there are no items. When I go on to his PC lots of items show in his outbox, but not when I view the account from my pc. We delay emails in the outbox so we can send chasers out at...

Cant See outbox items on a secondary Account