Looks like they are going into the arrangement for if the menu bar was set to be hidden. Have you tried setting the menu bar to hide, and then setting it to show again? I used to have this on Catalina but haven't seen it on Big Sur.
Yes I have, sadly it made no difference :-/ I thought icon layout was stored in the .DS_Store file but even removing that did nothing, asi didn't resetting PRAM and trashing Finder prefs.