Unfortunately, it is not very easy for Lenovo to buy the correct pen for its tab. As Matthias Hug has already written, not every tablet works with every pen. Even within the same pen family, not all pens work with every tablet. Before buying, it is advisable to look at the Lenovo accessory compatibility matrix. This can be found under the following link:

https://download.lenovo.com/pccbbs...

Here you have to select your tab and compare it with the pen. Important: When ordering a pen, make sure that the manufacturer's number of the pen you order matches.

Since there are two P11 Pro generations, you must first check with the matrix whether the pen is compatible with your generation.

This pen is not suitable for every laptop/tablet. This pen works directly if it is a suitable device, but if it does not fit the device, it is the wrong frequency that the pen emits.
As far as I know there are only 2 types of frequencies for these pens ;D
But I am not sure