Office 365 multiple accounts

I wonder if somebody could help me on my iPad I have multiple 365 accounts from different companies that I work with.

There seems to be a problem when trying to work on a another company is 365 account even though I have a login in.

So it is very frustrating as I have deadlines and need to fill in Excel, PowerPoint etc and return back to that teams account. So when working in teams and I am sent a file to work on and I need to login to that 365 account it just hangs please see attached photo.