Tiling in a level-floor shower

Well, there was this thread and actually has already explained how it has to be.

Ok, quite a few things seem to have been done wrong. What do you think, is there still something that can be done? I would rather not tear everything out again since it has already been sealed. Does anyone have an idea?

Check if is still feasible. If not, you won't be happy with the shower without a slope.

Check if is still feasible. If not, then you won't be happy with the shower without a slope.

Ok, I will check it today, what could still be done if it's not to make it fit somewhat? I'm really about to despair already.

Ok, I will check it today. What else would need to be done if it doesn't fit somewhat properly? I'm really on the verge of despair

Honestly? Get a professional; anything else will be botched work. I don't see any slope worked into the screed to the right or/and backward at the tile laid by the shower. However, that can be deceptive.

Check if is still feasible. If not, then you won't be happy with the shower without a slope.

Hm... but that would be even more difficult than my idea? Then the joint layout would be diagonal.

Without a slope in the screed, I don't see at all where it should come from?

Therefore, directly to :

Did you lay the screed level, or with some kind of slope?
If slope, yes, from where to where?