Bathroom / Water damage

Hello everyone
we had a severe water damage in the house. Our house is an old farmhouse which we have renovated gradually ourselves.
Due to this water damage, the grout in the bathroom has come loose and is now gradually breaking apart. We had some problems with our bathroom floor from the very beginning because such an old house is always moving. Cracks quickly formed in the grout, and we have already replaced the grout once.
Does anyone know our problem and have experience with it? Is a tiled floor even a good choice in our case? Alternatives to tiled floors in the bathroom? maybe wood? I am grateful for ideas / experiences. Thank you

Especially if the problem has already occurred, I see little point in laying the floor the same way again. Good PVC would be another option. Just lay it out but do not glue it down so that it has enough room to move. Or you could try cork, which as a natural material is not very moisture resistant but could adapt to the floor movements.

If water damage is already present, it would be sensible from my point of view to do something completely new here, meaning, remove the old floor, install new flowing screed, making sure to apply a barrier on the clay floor, or also to create a proper base with gravel and sand. Then nothing will work anymore, and then tile new on the screed.

Do everything completely new and do not stick to the old. Remove the floor entirely and apply screed. As described before, the subfloor is important. This can be done with gravel and sand. Then tiles can be laid on the screed.

But it's always a matter of money, which is why some just let the old concrete dry again and then tile over it. It wouldn't be my case, because mold could have formed here, which then slowly reappears.

that's why some just let the old concrete dry again and then tile over it.

That is indeed true, everything is a question of money. But after such damage, I would throw everything out and install a new floor. The mold formation that can arise should not be underestimated. Such a flow screed is a good option.