I had the same problem. That was the main reason we went to the Goshen rally this past summer. They came in cut out the old grout and replaced it, I think they use a new grout with a little more rubber in it. They even replaced three tile, it looks great now.
Pennie and Chuck, Mandi and Polly (the little dogs)
Hosted BamaGanza 2017 & 2018
2014 Georgetown XL378, 2014 GMC Acadia Denali Toad
The Home of the FREE because of the BRAVE