Good morning All!

I had tile removed and then new 18 x 18 tile installed over an Ardex base, using Mapei grout. We left the home for 2 days while the grout was installed and curing. Right away upon returning home, I noticed small pin holes in the grout and “rocky” looking clumps so I notified the installers and they came right out to asses. I was told the game plan was to dig out the clumps. When I returned home, I received notification that upon detailed inspection, there were too many spots to dig up so they “skim coated” it instead. Not sure what that meant but within 6 months, my Ivory grout is discolored and brownish in those areas. I reached out and it was inspected, so the next fix was to come out to the house again and remove all of my grout and regrout. Then Covid hit so we weren’t able to have that done yet. Several months later I noticed some tiles making a sound when walked on—kind of a popping sound. I reached out and they came out again and I was told there is likely duct work under that area and that when it is cooling or heating it is causing contraction or expansion. Is this something that I will have to live with? They will be coming in to remove the grout and regrout soon as they are back to running full staff and I am a little more comfortable with people in the house again, so is there anything they could or should do regarding the popping tile sound I hear while the floor is under deconstruction again? Tiles are not cracked, however I did notice a hairline crack in some grout lines in other parts of the floor. Also adding that the dishwasher and our slide in range are tiled in...it was extremely hard to remove the Dw when we needed to and we can’t remove the range to clean under...thank you! I should mention also that we have a full home filtration unit with a water softener...somebody told me that likely the grout color is uneven because the grout was mixed with our water? Could that have caused this or have caused any other integrity issues? Thoughts?