After the new toilet is installed, the bottom is leaking, and the water leakage is obvious when flus

I'm afraid you didn't recognize it when you installed this toilet. >>>More

The leakage is first because the toilet drain has leaked, and the first thing to solve is the leakage problem in this place, which may be that the hose is aging and cracked or the joint is not good, and then it is useful to seal it with glass glue.

This proves that the seal of the drain is broken, or the toilet drain is not aligned with the drain mouth, and the water is reversed when flushing, which can only be dismantled and reinstalled ,--

No, it's best to put it in place first, mark it well, move it away, make a circle around the mark, and then make a circle after putting it on, so that it will be more sealed! And it's not bad.

It should be that the water pipe inside the toilet is broken, or it has been displaced, and you should first check the water tank inside to see if the water pipe inside has been broken. If it wasn't a broken or displaced pipe, it should be that the toilet was blocked and the water was full.