iPhone 11 iOS 13.3
IPad 10.5 Pro iPad os 13.3
Outlook iOS V 4.21.0
Apple Watch series 3 watchOS 6.1.1

I have been using Outlook for several years without issue. The latest update has caused a very odd fault. In Outlook I have an Inbox and then >10 folders that I drag & drop emails into. Now when I get an incoming email, I get a notification and I can see & read it on my Watch. There is a Red badge on the Outlook icon but when I open the Inbox there is no email visible. If I toggle the Focused In box on and off the email will show up. I then go through each folder and open it. All previous emails download in to these folders fine except I get can anywhere through a couple or 7 or 8 folders and it stops loading the previous emails and freezers. All emails then disappear from earlier orders.
I have done everything I can think of the fix this. Signed out & back in. Deleted the app and reloaded and started from scratch again. All this without luck.
I have reached out to MS and they have not replied as yet.
Has anybody else got this issue or any feedback?
TIA.