I recently decided to do a refresh install of Windows 10 Pro on my 2 year old HP laptop.
After a fresh install from a USB stick I found I only had 10 Home on my laptop.
Pulled out an 18 month old image and installed that… sure enough 10 Pro.… also Microsoft online account showed 10 Pro.
Tried the USB stick install again… laptop now back to 10 Home…. and MS online Account now showed 10 Home.
In the end I installed the 10 Pro image again and did a Recovery, Reset, Fresh Install from within Windows.
So it appears that Microsoft online accounts does not keep or retain the most up-to-date Windows installation record for one of your computers.