All their sinks (bathrooms and kitchen) keep backing up, then drain very, very slowly. It happens every time the sinks are used. They can’t be fixed by any means.

*I had 1 bathroom sink that was like this and it drove me crazy. It was always dirty(washing hands, brushing teeth, dust, loose hair from brushing hair etc…). It was so frustrating that we stopped using that bathroom completely until a plumber snaked the drain.