Question about Lenovo Thinkpad Thunderbolt 4

I have a Lenovo notebook (P1 Gen 4) and also now the Thinkpad Thunderbolt 4. When I now connect this via USB to the notebook, I get the message: The connected AC adapter has a lower wattage than the AC adapter which was shipped with the system. This message appears directly in the BIOS/UEFI even before Windows has been booted. Why? I thought this Thinkpad was designed to work like this? Do I really have to connect the power cable to the notebook as well? If so, the competition has definitely done better (Dell and HP). I've already googled it and many show that it should work with a screwdriver. However, I don't want to take the box apart as this would invalidate the warranty and, more importantly, it's not my personal device. Anyone have a clue?