Hire professional to check better la. Don’t skimp on this.

Pipe leaking especially from inside the wall not easy to check urself unless it is very obvious. If your above unit no ppl stay also hard to check whether their pipe is leaking onot.

From my experience you might wanna check your drain. Be it bathroom or balcony. Stress test them see whether the water will drain out fast enough or not.

Haha somewhat true also