Will installing a bathroom cistern cause a leak in the sewer pipe?

If the bathroom sewer pipe exceeds the window by two tons, it cannot be renovated, and it should be negotiated with the developer.

The installation of the toilet sewer pipe must be accurate, and the socket should be glued, and all plugs must be plugged to the end. After the installation, the hole through the floor slab should be carefully filled with cement mortar to prevent water seepage in the future. After the water pipe is ready, the reserved water nozzle should be wrapped to prevent the cement from falling.

Hello, it may be that the toilet tank flushing there is not tightly sealed, the water flows into the pipe, especially at night, I haven't found the regularity, I feel a little related to the upstairs user after using the water, before and after several times to remove the ceiling gusset, no traces of water leakage were found, there should be no leakage, the sound from the thickest three sewer pipes in it.

This is mainly to see the cause of the leakage of the underground water pipe, what material is the ground pavement, the first thing to find the cause of the leakage, the location of the repair, whether to dig the tile to see the actual situation of the maintenance to decide.

There is a certain chance. But it's unlikely. Why didn't the workers get some waterproof glue on it when it was installed?