Install oven in Ikea Faktum base cabinet

Hello everyone, I have the following problem: After moving, I bought a new Faktum kitchen and took my old oven (Balay) with me. The good piece has already been connected by an electrician. Now the problem: The oven does not fit properly in the cabinet, there is about a 1 cm gap at the front. You can’t force the oven in no matter how hard you try. It seems to me as if the cabinet is just 1mm too narrow for the oven or if something might be hanging out the back (towards the wall). Am I just too dumb to insert the oven correctly, does Faktum have no standard size, or have you ever had a similar problem and can give me a tip? Thanks in advance!

The rails on which the oven stands have small indentations for reinforcement, where the oven can get stuck. If that is the case, the only solution is to push the oven in with a lot of force. However, place your hands or feet not on the top but at the very bottom when doing so.