I recently had the marble in my shower cleaned & polished and the grout repaired. Everything was great for the first few days but I noticed that there were areas of grout at the far corners of the shower floor that weren't drying - takes more than 24 hours or needs help of a hairdryer - but then the next time I take a shower, I have to go through the same thing.

I also replaced the trim on the shower at the same time (exact same model but a different style Hansgrohe). Is this a problem with the grout (i.e. not being properly sealed) or could there be a leaky shower valve?