Thanks to all of you guys for your help!
It was just like you described, one program was using the same shortcut as Evernote. In my case the program which caused the problem was the driver software for my CPU and GPU --> AMD Software: Adrenaline Edition (my old laptop had an Intel CPU and a NVIDIA GPU, I guess this was the reason why the problem didn´t occur there)
I deactivated the Hotkeys in the AMD Software because I don´t need them anyway and just like that, the shortcut for the Checklist in Evernote works again.
Thanks again for the help!