Outlook email client attachments not visible after first reading.

I've used Outlook for years, and have continued to use it on my iphones since switching from a WIndows mobile.

Twice in the last week I've needed urgent access to an email attachment.

I can find the email, and the summary page shows that there's an attachment, but when I open the email, there is no sign of any attachment. (Although I've previously read it on this device.)

I've tried forwarding the email to somebody else; the email arrives without attchment.

The first time it happened, I eventually discoverd that if I archived the message and then restored it to the inbox, the attachment returned, however this time I can't get it to show anywhere, and have to go to a proper computer and read the attachment (on Outlook) there.

I've tried all the "close the app" turn the phone off and on, reopen the app, type "solutions". The only thing I haven't done is delete the app and reinstall it - life's too short.

Is this just the usual "Apple and Microsoft" don't mix routine, or is it just me?

iphone SE2 iOS 15.7.1

The first attachment was a pdf, the second one a Word document.