Grout Between Tile and Shower Pan
I am hoping to get information regarding some work that contractors are doing in my bathroom. My wife and I bought a new house that has a stand-up shower in the master. We noticed that it was leaking from a corner and contacted the builder to have them repair the issue (as it is still under that warranty). They came out and ripped out the bottom row of tile and re-installed it (just the tile, not the Shower Pan or anything like that).
My real concern is this: They did nothing to seal the bottom of the tile to the Shower Pan. There is a gap between the two which would typically be filled with grout. The tile substrate is Hardie Backer (or some equivalent) with a Schluter KERDI system to provide a moisture barrier. We already have seen issues with the grout being damp on the outside of the shower (the same time and grout that was replaced). We had the builder out today and they said they are going to install a different Shower Pan but, when doing so, will still leave the gap between the Pan and bottom tiles (rather than fill it with grout).
So my question is this: Is there a requirement to install grout between tiles and shower pans?
My thinking is that leaving that gap is going to make the problem worse because a larger amount of water will be getting behind the tiles and will ferret around to find new places to leak.
Any help/advice would be greatly appreciated.