The screed outside the shower area has sagged

It is normal that I first disclose the information relevant to me.

No, it is normal if you disclose information relevant to the forum. For me, the question is wrongly posed, because

slope outside the shower area

130 for a shower length is simply not enough to shower safely without a shower enclosure – whether the screed is lowered or not. That doesn’t matter at all, it’s just a stupid consequence of "showering on 130 without an enclosure".

No, it is normal when you disclose information relevant to the forum.

My statement was meant to say that it is normal to initially disclose the information you consider relevant. When creating the thread, I cannot know which information is relevant to the forum. I also wouldn’t post pictures of my kitchen on this topic now, simply because I don’t consider it relevant. Of course, it is clear to me that you provide additional information upon request. I have done so (except for one photo).

130 for a shower length is simply not enough to shower safely without a shower enclosure - whether the screed is lowered or not. That doesn’t matter at all, it’s just a stupid consequence of the "showering on 130 without enclosure."

OK, thanks for the assessment.
Lowering the screed just causes water to run against a wall in the non-shower area and not into a drain, and that was not the case before. Since the walls are sealed, that is probably not a problem nor a defect.

So, I think we can end the topic here. ;-) Thank you very much.

No, the silicone joint is not cracked. Yes, I have, but the problem only occurs if water gets into the non-shower area for some reason. If you shower in a way that the water stays only in the shower area, everything drains perfectly. But if you don’t shower carefully so that water gets outside, or water gets outside for another reason, the slope in the non-shower area causes the water to run against the wall. I quickly drew something to illustrate the situation.

The screed slope should have extended all the way to the wall at the back. As it is, with 1.3 m it is simply too short. At least according to the sketch.