Look, at first glance everything might seem fine, but it might not be completely airtight yet; the main thing is that you don’t have to remove and reapply the silicone seals. I did this with my meat grinder because the internal adhesive had come loose slightly, and the motor wouldn’t start - it’s an electric one… You can try to identify the problem using the service manual for Moulinex Masterchef 750, it describes the disassembly and assembly process in detail since the manual is used in service centers and was written by engineers. But don’t worry - despite that, the explanations are very accessible. I don’t have a technical degree, and as a regular amateur, I understood everything.