This bug is affect the gameplay, however it not to important but will make some… “embarrassment” moment. Uhh, just look at the picture. My sims after work or after doing action, they clothes just randomly disappear for no reason (maybe Harry Potter do that?). However, this bug can be fix if you get your sims browse clothes, delete background application, reset device and etc…
that is their bathing suits, if you change their basic wardrobe swim suit option they'll wear that instead of the generic when they come home and want to take a swim
This forum is provided by EA but is designed as Player helping Player, in this case we can not do much more for you
Contact support: Get there in game: green ... button at the bottom of the screen; info > online support
Or use the web https://help.ea.com/en/help-top-issues/?product=the-sims-freeplay
Or contact support via FB or Twitter, links are at the bottom of the page
