I don't know if this bug is the same for all housecarls, but Lydia is the most well known one for not using her bed in Breezehome. Is there a way to fix this bug on PC?

I think someone told me her bed is backwards? Which is why she won't sleep in it.

Though truth be told I haven't seen a single Housecarl use their bed, and none of them recognize me as the occupant of the home anymore.