Upon depressing the main flush valve on our Thetford Aria toilet, the gate quickly retracts and then closes just as quickly.  Normally, when the gate opens and allows waste to flow to the black tank, there was a 2-3 second pause, for the waste to clear the bottom of the stool.  Then it refills, ready for the next cycle.  Currently we have to keep the flush valve depressed long enough for the waste to clear the stool.  Where did my "pause"  go?   Originally, I would push the flush valve pad and walk away.  Thanks,     j.

There is a toggle switch on the back of your toilet. You must have inadvertently flipped it to the other position. Feel behind your toilet and flip the switch to the opposite position. The position you want is called residential mode. Hope this helps.