Window is leaking! Is this normal with dry glazing?

Hello everyone,
there is water and dirt between the pane and the frame of my plastic windows, which are about two years old! The window seller told me this is normal because it is a dry glazing. My question now is whether this is really normal? I have already looked everywhere and so far have not seen similar dirt and water accumulations inside any other window.

I've never seen that either. Paging

With my approximately two-year-old plastic windows, water and dirt are standing between the pane and the frame! The window seller told me this was normal because it is a dry glazing.

I have never seen that either. Paging @11ant

Sealing was done in the era of single-pane glass, which was a long time ago. Pane packages can also be sealed with silicones—probably with foams, which are mostly misused (and "for safety" preferably overdosed) materials in construction. If that were suitable as an adhesive bond, on the other hand, a non-destructive replacement would become more complex and significantly less likely to succeed.
Here, the problem is probably a combination of unclean production conditions and insufficiently sealed pane package. Apparently, some window sellers are also not aware that the medium between the panes is not breathable air.

Thank you for the quick response! What would you do in my place?

Almost all plastic windows have dry glazing. It is not normal for so much water to get in there. The pane might be incorrectly installed. The water also looks more like condensation, which would mean that once water has gotten behind the seal, it cannot drain or evaporate from the frame.

What would you do in my place?

I would check very carefully whether the warranty period is still running and claim the glazing unit and have it replaced,

It is not normal that so much water gets in there. Perhaps the glass is installed incorrectly.

The water did not actually come in like that. It is not that the glazing unit in the sash is installed incorrectly, but rather the unit itself. It was not produced sufficiently tightly and is not sealed.

The water also looks more like condensation, which would mean that water that got behind the seal once cannot drain or evaporate in the frame.

Condensation, yes, but not running behind the seal, but precipitated from air that has penetrated into the glazing unit.