Hello crinrict . I can confirm that I am on patch 2.28 as of right now.
I started a brand-new test save and followed the same steps I had done in a previous save prior to this report where I had the problem originally just to make sure. Enable Rental Unit Events has been unchecked this entire time. I played for a little while and still got an event, the Tenant Revolt event. Then I tried following your instructions, saving, shutting the game off, reopening the game, and turning the setting on, then off again and played for some more in game days, about a week I would say. However, I got another event, the curse book event. So yes, it seems that the toggle is still not working as intended. Events still happen whether it is on or off. All of this was tested today on a new save.
The Sims Team