Cannot connect Apple Pencil 2nd generation to iPad Pro 11" (M4)

The new 2024 models of iPad Pro and iPad Air do not support the second generation Apple Pencil. Here is Apple’s definitive compatibility list for Apple Pencil and iPad:

Apple Pencil compatibility - Apple Support

Different models of Apple Pencil use different pairing and charging interfaces... 

While the new Apple Pencil Pro is similar to the second generation Pencil, due to a redesign of the inductive charging system, the Apple Pencil Pro is only compatible with the just-released 2024 iPad's Pro and Air. This Pencil is not compatible with any other model of iPad.

The USB-C Pencil can also be used with any model of iPad that features a USB-C port.

In summary, the Apple Pencil models are not interchangeable - and can only be used with the iPad that has appropriate internal hardware.

Apple Pencil 2cd generation is not compatible with M4 iPadPro.

Here is the Pencil compatibility link:

Apple Pencil compatibility - Apple Support

The title of this thread explicitly refers to an iPad Pro 11" M4 - this model having been released earlier this year.

If you have some other iPad, then this will not be the M4. You can find your model name in iPad settings:

Settings > General > About > Model Name

Not sure which iPad you have? Identify your iPad model.

Apple's naming conventions can sometimes be confusing.

The newest models of iPad - namely the iPad Pro M4, iPad Air M2 and iPad mini A17 Pro - are simply identified by these names, and not currently identified by their "generation". Presumably, at this time, these specific models sufficiently differ from earlier iPad models that a generation identifier is not considered by Apple to be necessary.

Hopefully Apple's compatibility list (link already provided) will remove any ambiguity.

As an aside, this feature comparison graphic may be helpful in understanding some of the functional differences between the four different versions of Apple Pencil: