I have a 2 year old Toto Drake that was installed by a professional plumber.
Two weeks ago it got clogged - not sure why - maybe too much toilet paper - I don't have any kids who could have thrown anything in.
I used Drano Max Gel which didn't work. The plunger worked.

Now it seems to flush ok, but the tank refills every 30 minutes or so even though I have not flushed.
I watched inside the tank and the water level drops about half an inch. I also watched the bowl and that also seems to drop a bit. When the tank refills the water in the bowl goes up a bit and then slowly goes down. Same for the water in the tank.

Seems very odd to me how both the water in the tank and the water in the bowl can go down. I don't see water flowing into the bowl and I don't see a leak anywhere.

What's going on and how do I fix this?