[retiredguy123]

The cannister is pretty standard for the newer toilets. It has the same function as the older flappers. At the bottom of the cannister, there is a yellow (or red), 4-inch diameter gasket that you can buy at Lowes or Home Depot for less than $10 and they are very easy to replace. If you have trouble, watch a YouTube video. I assume that is what Mike Scott Plumbing replaced, but it may still be leaking. I would try cleaning the gasket and the ring that it sits on. If that doesn't work, replace the gasket.

Another possible issue that can cause this problem is a leaking fill valve. After you flush the toilet, the water level in the tank should rise to about one-quarter inch below the top of the cannister, and then the fill valve should shut off. But, if the fill valve has a slow leak, the water may continue to rise slowly until the water overflows into the cannister. To check that, flush the toilet and check the water level in the tank about an hour later. If the water level is at the top of the cannister, then you probably have a leak in the fill valve. Again, it is very easy to fix.