Sims wearing hats on nude outfit

I've has this issue since the Enchanted Living patch - I assume it was to do with the new headwear category. I've tested it on old save files and new save files, on sims already in the game and sims I've added to the game. It happens to the bathing outfits of all sims incl. children taking a bath or shower. I have No Mods or CC. I don't currently have script mods allowed.