What did the inspectors say when they inspected your flood test? Otherwise id have to say it looks like a nice shower sans the sliver cuts/layout and yes the floor looks moist and that may be an imperfect grade or pool.which is to the point about the water testing process so often laughed at and skipped. but looks arent the key to success.. is that Drywall in the niche? thats poopy.

What you're seeing is from the thinset. Thinset is a chemically curing product. The gasses that are released during the curing stages are passing through your stone. 100% normal. Will take a few weeks to a couple months cure properly.

I agree with thatsmuchbetter. I don't see any water proofing anywhere in the install. What was used behind the tile prior to installation?

Thinset at that thickness for your application with a breathable stone install cures in less than 30 days with a thinbed shower pan like you have . It should have initially been given a full cure prior to introducing water(after grouting). There is also rapid set thinsets that cure faster and theres also the wrong type of adhesive such as mastic or PRE mixed bucket grade glues. we dont know what you have.

Dont be fooled by misinformation from some novice sales people on here about 2 months.

If you want to verify if you have a grading/pooling issue as the cause. you stop using the shower. For at least a handful of days and perhaps put a dehumidifier in the shower to fully dry it out. it will either dry out and clear up or not. only time will tell.

Since you have a thinbed pan you arent hurting anything(unless theres a pan leak not verified ) and best get used to it. The only other issue could be poor application of the wrong type sealer in that particular spot also not hurting anything. You chose a fickle material for a shower floor. and now reap the rewards.

and you never clarified the flood testing process which is the only way to catch and correct a poor shower pan install before leaving a client with a wet mess like you may have...

thatsmuchbetter, just for my own information down the road, what is not considered a "fickle" material for a shower floor?

I've used that exact tile as a backsplash. Yes it's fickle. What kind of grout was used?

I believe the dark tiles are the ones that have a rubbled appearance (either the ribbed one or the rough one). It is nearly impossible to rinse grout or mastic from the surface of that particular tile. When it gets wet the grout darkens.

porcelain

Well said young lady

I wouldn't expect an installer to know that thinset is a chemically curing product, not a moisture to air curing product. Thinset releases gasses when it's curing, not moisture.

I wouldn't expect a tile hack to know that. I would expect a tile contractor to know that. If the tile contractor doesn’t know as much as the designer on the job, then he’s not a tile contractor. I expect my partners to know more than me. Not less. I expect to learn something from them on every single job. Not to teach them how to do the job.

I don’t think that I have unreasonable expectations of knowledge and professionalism. But I also expect to pay well for that and can consequently have those expectations. It’s not reasonable to have similar expectations from a $1.98 hack which is where most Houzzers go wrong.

And you know what type was used do you? Look at the pdf file of a few rapid set mortars. Mortars. And then educate yourself on dryset mortars.