Some grout was coming loose in my shower stall, especially around the drain. One tile, when I pressed down, I could see bubbles when there was a bit of water pooling around the tile. I assumed a loose tile or cement was dissolving underneath

I removed the grout and tried to pry the tile off, it wasn't easy, so I gave up in case I broke the tile (didnt have a replacement).

I regrouted the entire showerstall floor, all of the other grout dried (chalky appearance), but the area that was the initial problem, still looks wet (ie. Not like all the other spots). What should I do? Take everything out and try again and this time try to take out the tile to see for moisture contamination (its only one tile - the one right by the drain pipe)