Process problem with the Ikea Atlant siphon

Hello,

my first post here, and also my first problem.

Our new Faktum kitchen in Abstract Red is really great. However, I have a problem with the water drainage in the Atlant.

From my layman's point of view, I have installed everything correctly, but the water drains very, very slowly from the sink. As soon as the dishwasher pumps out, water is even pushed back into the sink.

The strange thing is, if I take the drain hose out of the wall drain pipe and hold it into a bucket, everything flows perfectly. Also, if I only insert the drain hose one centimeter into the wall drain, it drains, but water also runs beside it.

Does anyone have an idea? - I don't like it this way!

From the picture, it seems to be correct. I would just try to turn the siphon towards the back right and then lead the hose "straight" into the drain pipe. As far as I can see, there would then be more space in the cabinet and the hose would lead more steeply into the drain pipe. Otherwise, it sounds like the house installation might not be in order. Was it better before?

From the picture, it seems to be correct. I would just try to turn the siphon to the back right and then lead the hose "straight" into the drain pipe. As far as I can see, there would then be more space in the cabinet and the hose would run more steeply into the drain pipe. Otherwise, it sounds like the house installation might not be in order. Was it better before?

I'm slowly beginning to fear that it is due to the drain pipe. Because recently, the washing machine has also been pumping water into the sink that is in the other room and not connected to the siphon.

With the old sink, everything ran smoothly, but that may also be a coincidence.