Toto Drake leak

We have a Toto Drake toilet that is about 1.5 years old and love it but... it now seems to have a leak. There is a constant running water sound or hiss and in investigating we see that it is watering running out of the tubing into the overflow pipe. I think the tank is no longer seated correctly because if you push on it the leak stops.

This started happening when my 5 year old son would push/lean into the seat thus into the tank when he was going. We've stopped the habit but now have an issue with running water and hissing noises.

Any ideas what the problem is and how it can be fixed?

Push on the tank or the flapper?

Pushing back on the outside of the tank seams to stop it.

It sort of sounds like the filler valve is not shutting off properly, allowing the level to get too high and running out the overflow. Depending on whether it is the older (probably) or the newer fill valve, if it is the older one, you can buy a repair cap for a couple of bucks at Lowes. Takes all of about a minute to replace. If you check out the Korky website, compare the valve with what you have, and then pick up the cap assembly.

Note, if the tank wobbles a lot, you can tighten it up some. Do it evenly, a little at a time one side to the other. You can get it so that it is almost touching.