We have a standing shower with a strange leak. It was built with a small tiled wall/step that the frame-less glass shower wall panel sits on. I noticed water pooling outside the door after a shower. At first I thought it was the door seal but upon closer inspection it is coming out of the grout. See pics (right where the arrow is pointing). The shower was already in the house when we bought it so I don’t know anything about how it was constructed.

How should I proceed trying to fix this leak? Do I need to re-do the grout? Should I just use grout sealer? Any help appreciated.