iOS Devices - Company Portal - Requiring registration every 5 minutes

iOS devices - Open up Company Portal but it tells me this device is not registered. 5 minutes later, I open up Company Portal again, it appears as "This device is not registered" again. As a result, it ends up creating another device entry with the same name in Intune. I've ended with multiple entries which I've deleted.

I've tried almost everything possible:

Extra entries have been deleted

CA policies that require compliance or app protection completely removed

App protection completely removed

No issue with device limit

Enrolling with ADE, User affinity

Device wiped multiple times

Latest iOS installed

Device is in ABM

Android devices seem to be fine

That said, it does still let me deploy apps, wipe device etc