Problem with running water in an apartment

I have a problem with running water in an apartment in Skopje. It flows continuously without interruption and the damage is increasing day by day. If anyone has had a similar problem or is knowledgeable about this topic, please help me because I don’t know what to do.

Historically: I bought an apartment in Skopje, Karposh on the 4th floor out of a possible 5 (in an old building, the 5th floor above me is an extension) somewhere around February, everything was fine until sometime at the beginning of June when for the first time in the WC on the ceiling it started getting damp. I called the master, he cut the plaster where it was the most and we saw a hole and through it you could see light from the sun even though I’m not on the top floor (it turned out the previous owner cut the chimneys). I fell on the roof and covered/closed the chimney (it was during this period that there were storms in Skopje).

After this the moisture dried up and everything was fine until two weeks ago when it started to flow again and much more than before, now even in the bedroom at the other end the moisture is getting more and more, the whole slab is drowning wet and most of all near the chimney and it is easiest for the water to break through and from there it rains non-stop all day. Since the building is plastered and the neighbor who is plastered with me from the other entrance, he also has a problem similar to mine.

Now, the time when we closed the chimney on the roof coincided with the period when the neighbors from the other entrance on the 5th floor were not here for a month or so (after they returned, it started leaking again). I thought the problem was with them.

I called plumbers every day, they came 5. The apartment above me and the apartment next to it from the other entrance were all checked, but nothing special was found (only the neighbors changed the shower faucet).

I also called Akwaseiv, as professionals in the area, they checked the two apartments with a camera through the pipes, they took 10,000 days and did not determine anything, and they established that the two apartments are without problems and that I do not have any leaks from them.

I don’t know what to do, how would I locate the problem, if someone had a similar situation, please share your experience.