I checked the tile grout.
Transition from wall tile to bathtub lip.
Above the lip of the tub.
This gap may widen over time as your home shifts.
The tub is designed to sit on the floor and be screwed to the studs kohler recommends setting in mortar which i did.
Was the shower water seeped to the lip area from the bottom caulk and then travelled laterally out and wet the dry wall adjacent to the tub.
This kohler acrylic tub is thick the flange is more than a 1 2 thick if you run the cement board over the flange and the tile which is about 1 2 thick when thinsetted it will come too far into the tub.
Similar to the gap that can exist between your wall tile and tub you may have a space between the floor and your bathtub.
I cover some of the specifics of how to layout and set up a tub to install tile around it.
As with any other gap near your bathtub you ll want to close the opening to prevent any possible water damage or the onset of mold and mildew.
This video will show you how to set tile around a tub.
Then apply a generous amount of thin set to the bottom bathtub tile and position it 1 8 in.