Insane Landlords--What Can I Do??

My little sister (20F) is renting a house in a college town with some friends, and her landlord situation is so awful/confusing and I just don't know what to do. For context, I'm a landlord myself (and I would NEVER do the things they do lol) but I'm posting here in hopes it'll reach a wider audience and I can get a range of advice.

The landlords are/were an older man and woman, presumably his wife, and they just hired what we think may be a property manager (though this was never really communicated, and he referred to himself as "their new landlord" once + insinuated a sale of some sort). Very confusing. The old landlords made the girls feel really uncomfortable, so they were glad to hear that they were out of the picture. Though this may not be the case apparently.

There's eerie and creepy stuff going on. The PM showed up one morning because "there was a broken toilet in the house." None of the girls living there had reported one. When my sister asked where he'd heard that, he said the landlords had reported it. And to my knowledge, there was no broken toilet to begin with. But how would they even know if there was??

There are also cameras installed outside, the landlords show up randomly, and they try to parent these girls when they're around. It's so freaky. There's SO many other instances but I want to keep this short. Any thoughts or advice?? I feel like I should know what to do as a small LL but I truly don't. We don't even understand who owns the property right now. Any and all thoughts appreciated. TYIA