The bathroom floor tiles and wall corners are soaked in water

This problem is actually due to the fact that the floor tiles at that location are lower than the floor drain - the water flows to the lower place. At that location, not only will the water on the surface flow there, but there is also water stored under the floor tiles - the original ground should also be at that position relatively low, and some water enters under the floor tiles from the gaps in the floor tiles, because this position is relatively low, so it can't get out, so that situation is caused.

There are secondary drainage holes under the toilet, this master should not have done it for your family, and there are a few bricks that are lower than the floor drain, which is also the master's level, only the floor drain is the lowest. The water first flows away from the floor drain, and then some of it will always seep into the floor tiles, so that a small hole will be smashed at the edge of the bottom sewer pipe, which is called secondary drainage. You have stagnant water, is it full underneath?

If your neighbors are decorating, ask someone else's mason to help you look at it, and find a few more to hear different opinions.

This needs to be dealt with, ask a master to replace the floor tiles, and the water will seep downstairs after a long time.

It is best to dig out the bricks and then make waterproof and replace them with new bricks, if you don't want to change them, you can call them waterproof to make a transparent waterproof for you. But it won't last a few years.