Lightroom Classic 14.2 won't import presets

I had to upgrade to Lightroom Classic 14.2. Now I cannot import any of my valuable User Presets that took me hours to develop. When I import an *.lrcat backup file, they won't show up. When I try to import the *.xmp files directly from Lightroom Settings/Settings, I get a notification "Unable to import presets / All items were already imported." But I cannot see them anywhere and cannot use them. what has gone wrong?

Thanks"