Ikea Utrusta floor hard to use, experiences

We installed a Metod kitchen last week. The assembly using a wall rail went very well overall.

However, now we have the following problem:
The Utrusta shelves in our 40cm and 60cm base cabinets are very difficult to insert. You have to press quite hard at the back of the cabinet to get the shelves into the correct position. We are now concerned that the cabinet carcass could be damaged by this tension.
Loosening the screws to the countertop and to the adjacent cabinet unfortunately did not relieve the tension in the carcass.

Do you perhaps have any tips on what else we could try!?

Hello, first measure whether the corpus narrows towards the back or whether the shelves are not cut correctly.

The width of the corpus and the shelves have almost exactly the same measurements (+/- 1 mm)

By the way, I just received this response from the Ikea Helpdesk.

"According to our experience, the shelves fit very tightly. It has no impact on your corpus. If you encounter major problems during assembly, please contact customer service in the furniture store with the original purchase receipt."

I think everything should be fine then.