In its updated Apple Pencil support document, Apple has warned users of a bizarre interference issue between the second generation Apple Pencil and car key fobs. Apple notes that in some cases, charging your second-generation Apple Pencil with your iPad Pro in the vicinity of a car might prevent you from unlocking it with a key fob (via 9to5Mac).
The bizarre signal interference between your Apple Pencil + iPad Pro and your car’s keyless entry device may occur when you are carrying your Apple Pencil and iPad Pro with you while headed to your car, or if you may be carrying the Apple Pencil and iPad Pro in a backpack while trying to unlock your car.
According to Apple, the issue only occurs when the Apple Pencil is actively charging. This means that if the Apple Pencil is magnetically attached but fully charged, the interference will not occur:
If you’re charging your Apple Pencil (2nd generation) with your iPad Pro and your car’s keyless entry device (key fob) is nearby, signal interference might prevent you from unlocking your car with your key fob. If this happens, you can simply move your iPad Pro away from the key fob or remove your Apple Pencil from your iPad Pro and store it separately. When Apple Pencil is finished charging, any resulting signal interference will cease.
Have you noticed any interference between your Apple Pencil and key fob?