I usually see the not able to cope with the volume. I have also seen trap primers and regulators not set correctly so the toilets won't properly flush. I have a

I usually see the not able to cope with the volume. I have also seen trap primers and regulators not set correctly so the toilets won't properly flush. I have also never understood why a plunger or a toilet brush was not available in the stall. I keep one in my bathroom so if there is an issue I can address it easily and quickly. Not able to keep up with the volume is more common than in should be.