thanks jonas!
this happens randomly for me, so unsure if i can really test this. However i have put in the setting now to apply to every user.
it was still happening, just had an occurrence over the weekend. hopefully this key finally resolves it.
im on 1903 currently, so hopefully the key is backwards compatible and effective. I am not moving to 20xx for at least a year.
Now that i know what key it is, i could search that key and come up with some interesting results. This here article, provides more context on how to check it:
https://www.windowslatest.com/2020/06/07/windows-10-full-screen-setup-prompts-are-back/
just go to settings -> notifications and actions and check if "Suggest ways I can finish setting up my device to get the most out of Windows" is checked or not. I can only find this setting in version 2004 which it appears taht some of my machines have auto upgraded to.. DAMNIT
(edit i should say that the machines with this problem are still on 1903, but the SETTING in the settings application only appears on 2004)