ceiling water stain cause 2

https://getceilingleakfromaclife.solsticebrief.com/posts/how-to-diagnose-a-ceiling-leak-from-ac-vs-a-roof-leak

A ceiling water stain usually comes from a leak in the roof, an overflowing bathtub, or a burst pipe in the floor above. Over time, the water seeps through the ceiling material, leaving a yellowish or brownish mark that often grows in size if the leak isn't fixed. That discoloration can also bring mold and peeling paint.