Company Portal on Windows 10 Installs OK but then reports Error installing itself

Hi Rudy, That's just it - the assignment was only required (not available) and to devices as System. I had no idea or clue how it suddenly started showing up for the users in their Company Portal as failed.
The only thing different to my normal customer Intune / Hybrid implementations is this time a colleague has implemented SCCM co-management and we are setting all the sliders over to Intune to win out over SCCM for the pilot group until we have rolled out to all in prod.
What am I missing here - as far as I know what is happening should not be and I don't know how to proceed after diving into the IME logs 😄
The Intune Portal reporting shows no errors at all...

And Company Portal had never been installed on these devices before they were moved into SCCM co-management and then through that Intune Hybrid Joined...
I have moved from a device installation as SYSTEM to a user assigned installation in the USER context to see if that will solve matters for new installations.
Testing today. So strange.
One thought - we had to get them to open SSL inspection through firewalls for a bunch of MS sites so that Company Portal and other things would even install, and they have an Always on VPN running also... could there be some further FW routing that needs opening or excluding from SSL inspection that might cause a detection failure on a perfectly good and well installed app? Just spit balling here... better that than ******* into the wind. 😄