Works only if i do the exact steps there, new explorer windows, DONT minimise it, then do the update.
but this issue happens even when explorer windows are minimised, so i don't think this is the whole story, but perhaps making steps towards it at least!
It is worth noting that on 11th April, @KingWigglett reported that the pop-up issue can be mitigated by minimising Explorer windows via the "Minimise" button (top right), but that if the window is minimised via other means (e.g. Task Bar icon or WIN+D), the issue still occurs.
Having said that, I am unable to reproduce the issue using the gpupdate steps when the Explorer windows are minimised via any means, so you might be right that this is only part of the story.
Big thanks to @Bill Moller for spotting the link with group policy and allowing us to move forward, and for @Michael_Michael_1 for the gpupdate /force suggestion. We should now be able to provide evidence in the form of a recording for these steps - which was requested by @Mitchell - MSFT back on 10th Jan. I will also note the progress on the related MS Feedback entry (https://aka.ms/AAjevpi).