Well everything is sealed well. There aren’t any holes in the grout per say. Those white spots are where thinset was too high in the grout lines.

Sealing tile does not mean the shower is waterproofed. If a shower is properly waterproofed you could shower in it without any tile on the walls or floors!

There are NO products that will waterproof tile and grout, meaning as Millworkman said, you most likely have a moldy mess under the tiles. And you can't just replace the floor tiles. The whole shower needs to be redone because the walls and floor in the shower need to tie into one another.

Why does the whole walls need re-doing too? We are having no issues there. I would assume if the floor got re-done we would just re-do the bottom few rows.

The tiles themself when I rub my finger on them and smell, smell a bit like vinegar or have a sour smell to them. Any idea?

If the was not built correctly and needs to be completely redone, it is more than likely the same crap was done for the walls. Grout and or Sealing the tile does nothing to stop water infiltration unfortunately.

Wait also I should preface this shower is like 1.5 years old.

we don’t do anything diy anymore regardless. The plumbing and build out was all done by a licensed contractor. Red guard too. The only thing we personally did was the tile.

Well it's obvious the licensed contractor did it wrong.

"And you can't just replace the floor tiles. The whole shower needs to be redone"

That is not necessarily true as it depends on how it was waterproofed. One of the advantages of the old-school method employing a vinyl pan liner is that the shower floor can be repaired without removing all of the walls. Assuming that the wall waterproofing was done properly.

RedGard was mentioned, but I fear it was not done properly.

cat builder, they did the shower 1 1/2 years ago. I doubt it was done old school.

Here’s an ok photo of the redguard when it was put on

Here’s another in progress photo