It seems to be the same issue as this one, that is labeled [FIXED]: https://forums.ea.com/discussions/the-sims-4-bug-reports-archive-en/fixed-fr-rental-protest-unsolveablerevolt-on-5-units/11660362
I maintain and fix everything, even in my own sims unit. I get a 5* rating. The tenants give me thumbs down when asked about the conditions and won’t tell me/my sim what’s wrong. The tenant/tenants revolt, my sim ‘promise better conditions’ but it keeps failing, and the rating drops to 4*.
It happens in both of my rental units.