Too stupid to install a full extension in a built-in wardrobe

Hello,

we bought the Faktum tall cabinet for microwave/oven drawer/door with 2 x RATIONELL full extension, deep, silver-colored.

Problem: we cannot install the sliding rails because they are too long (just barely, but too long). These built-in cabinets have a back panel that is recessed much further inward than usual (I assume for the connection and ventilation of the appliances). Because of this reduced space at the back, the sliding rails do not fit.

I don't understand where we went wrong, the purchase plan was compiled by the kitchen consultant and what we received seems to correspond to the system.

Usually, the sliding rails, e.g. the lowest ones, are mounted at the first hole of the cabinet and at the lower hole of the sliding rail. To do this at the front hole, the rail must be fully retracted so that the screw can be properly reached with the tool. And here lies the problem, as this is not possible because the rail is too long and already hits the back panel.

So it seems like the part is too long, but I wonder if that can be the case if all descriptions/product assignments actually fit. To illustrate, I took out the page from the monthly plan where the installation is shown. The red line is supposed to show where the third row of holes from top to bottom actually is, because shortly behind it the recessed back panel comes:



Probably it’s already too late and I can’t see the forest for the trees anymore ...
thanks for any tips!

And for good reason, the cabinets are ventilated from behind, otherwise someone might get the bright idea to install the back panel and then put a refrigerator or oven in there, the certain death of the appliances...