tavern beds with no global ownership variable assigned, so no legal bed renting possible.
Checked Bal Oyra and Ranyon-Ruhn, may be others (I think this is one of the bugs that may iterate between releases)
[Edit]List so far (Ranyon-Ruhn not working was probably some mod conflict)
Bal Oyra, The Black Ogre Tavern
Firewatch, The Howling Noose
Firewatch, The Queen's Cutlass
Llothanis, The Water's Shadow Tavern