I haven t used water for more than a month, and the walls of the toilet are still seeping

It's going to take a year to do it - that's nonsense!

In order to find convincing evidence as soon as possible, you must have a plumber do a pressure test with a pressure test pump so that you can find out if there is a leak in the water pipes.

One thing is for sure, that is, the waterproofing layer of your home is broken, or it was not done well in the first place - it is not that you see someone applying waterproof paint and you can assume that it will not leak. During the construction process, if the operation is not done properly, and the ground (including the wall) is not properly protected, the waterproof layer can also be damaged.

Of course, if the water pipe is outside the waterproof layer, then even if the waterproof layer is not damaged, then when the water pipe is leaking, there will be water seepage on the wall outside the bathroom.

Now, you can only do the suppression test first.

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You apply some ink to a wet area, and the ink goes down first, and it's a leak upstairs.

The water supply pipe is seeping, turn off the main gate and see if it will be done in a few days?