Toilet bowl water level slowly drops.
My toilet was flushing poorly, after a good session of plunging it is working decently again, however another problem has arose. When the toilet is flushed all waste is taken away,then the bowl refills as does the tank,OK so far. When the tank and bowl are filled, what happens next is that the water level in the bowl slowly drops, to the point that appears to be the level of the toilet trap. What could be making this happen?
All other household plumbing appears to function properly.
Theo