I think that you are totally right - there is some bug in Windows 11 that just makes the Icons disappear. People seem to have workarounds to make them come back, but no-one has a reliable way of preventing it. What I found is that there is no obvious pattern - I did try things ( Like removing icons) which seemed to work short term, but then it came back again.
The only good thing I can say, is that without me doing anything, the problem seems to have gone into remission, and I have only had them disappear once in the last couple of months - mostly everything is OK now. No idea why !!
It's definitely an Windows bug, affecting a lot of people, and its been around for quite a long time.