Went around to all the sinks in the house and did maintenance, changed tap washers etc. The seat on this bathroom vanity is toast though. It has a massive void in it. I couldn't work out why it still didn't seal with a new washer. I could not get my finger in there flat to feel the seat but I could detect the void with my fingernail. The photo shows the void in the seat after a very light pass with the seat cutter. The initial pass was just to visually identify the void.