Can't seem to get this spinning wheel to stop.
Occurs only at the home screen.
I've tried closing all apps, powering the iPhone off, flushing the memory but nothings working.
Have you tried signing out of iCloud and signing back in? Perhaps checking in Battery settings to see if something shows up there that is running that might suggest what might be using the device?
You could perhaps look into location services, in particular system services there, to see if something might be doing something there too. Beyond that you could try some other settings like Background App Refresh, Siri, Screen Time, Automatic Downloads (for iTunes & App Stores, and anywhere else), etc. and see if disabling them might make a difference.
Beyond that, short of potentially deleting various apps to see if one of them might be causing it in some way, which is probably not that likely as it's probably some (sync) type of service or something like that, you might be down to trying something like resetting network settings if not even all settings.