@Emilia42 I've found in several searches I've done lately that the filters don't stick. I've gotten mostly Entire Home and Hotel Room listings in searches for Private Rooms only. I've gotten No Pets properties in searches for "Pets Allowed," and so forth. This is probably by design, because users will quickly move on to another platform if their search generates too few results.
@Paula1486 If that filter is also not working for you, the next best thing would be the Price slider, as Private or Shared Room listings tend to run well below market rate for Entire Homes.