Wetroom linear drain installed wrong, what can I do?

That was a poor finished but I will advise you that if the water is draining without settling around the tile is not a problem. My advice whenever you are hiring someone that person need to do the job that will makes you happy.

Hi As you have several concerns I would start from basics. Any professional would start from scratch. You have wet grouting which suggests water ingress. Obviously you need to you need to make sure everything thing has been done correctly. You need to get someone in to view the problem to give you the correct answer.

Linear drain should finish level with top of tile The cross water low level trays come with the linear waste built in and avoid the need for tiling the shower base. Kudos also make a wet room former which can be fitted in a wooden floor or concrete floor. The most important point is the waterproofing of the area under the tiles by using either of the trays above you avoid the problem of water leaking through to the underfloor .