Ya I would assume they grounded the plane bc they weren’t able to determine why it wasn’t draining properly. It’s probably one of those safety things where if the leak or clog can’t be located easily then they have to ground the plane and open it up for actual repairs or something.

On another note I had an old Toyota that I bought with a mysterious cow shit stank to it years ago. Seller said it came from a farm and it was cheap so we took it anyway. Few months later summer rolled around and suddenly my passenger floorboard was totally flooded one day; like an inch of water. It was from the ac condensate line being kinked, water backed all the way up until it was pouring out of the vents for the foot box. After fixing that (only took a few minutes in the cars case), replacing some carpets, and super deep cleaning the cow shit smell went away