New Toto Drake's tank is not sealing.

We recently installed 3 Toto Drake toilets. Two of them are leaking from the bolts on the bottom of the tank (both of them just from one of the bolts). It is not a contant leak. It doesn't happen when we flush the toilet. Usually 2 or three times a day we will hear water starting to drip (like a shower slowly dripping) it lasts only a couple of minutes, but a significant puddle of water will be on the floor.

You may need to tighten the large nut on the bottom of the tank.

Here are our instructions