What does this mean when my flooring is like this? (pics)

[nambind]

The wooden flooring outside the bathroom has warped as in pic 1. And just near it the bathroom floor grout has got pushed out in a strange way all over, as if someone's pushed it out from underneath (pic 2). When I google it says that it's a water leak that makes the wooden flooring warp like that, but apparently there's no water pipe in that bit of floor (we had the flooring redone recently).

I'm very clueless about these things so just trying to learn. Could someone tell me what this might be please, and what sort of tradesperson I need to fix this.

No expansion gap left next to skirting boards......common fault...people often fit right up tight to skirting...its wood so moves....but that looks more than that.

it is wood, and it expands widthways (not length) when it is damp or humid

wooden flooring systems are usually marked "not suitable for bathrooms or kitchens" for that reason.

the stuff rising out of the joints looks like mortar or possibly efflorescence. scrape a bit off and put it in a cup of ht water. does it dissolve? is it gritty?

wooden floors are not supposed to be grouted

is it on a concrete floor?

who fitted it?

just looked at the pics again..why is there grout on a wooden floor...??....very odd !!

Looks like a combo of bad install (no air gap, and no join or support on the side nearest the camera). And the way its warped if sat its also getting damp. Is there a proper vapour barrier and foam underlay?

*I'd say

Guys, to clarify, the wooden floor is the brown one that's warped (pic 1). It's not inside the bathroom, it's outside on the landing. The grey flooring with the grout is the bathroom (pic 2) and it's tiles (though it looks like wood).

I will put the powdery thing in water and report back

I think it's damp, basically. Either coming through the floor or from a water leak that has spread under the flooring.