not connected Apple Pencil 2 to iPad Pro

After ANY iOS/iPadOS upgrade/update, you should ALWAYS perform a simple hard reset/forced restart of your Apple mobile device.

For iPad models with a Home button, do a simple hard reset/forced restart of your iPad by holding down both the Home and sleep/wake/power button simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.

OR

For much newer design iPad models, without a Home button, try the new simple hard reset/forced restart procedure for the new 2018-2022 iPad Pros, 2020/21 iPad Air 4 and 5, the 2021 iPad Mini 6 and the new 2022, 10th gen base models,

1. Press and release the volume button closest to the top Power button

2. Then immediately ( and quickly ) press and release the volume button farthest from the top Power button.

3. Then, press and hold the top single sleep/wake/power button You will see the Slide to Power off button, but keep on holding down the power button until you see the Apple logo, then let it go.

Once you have performed all the steps, wait for a few seconds and your 2018-2022 iPad will boot up completely to the iPad’s Lock screen.

Tap, read and follow this Apple support link below.

Force restart iPad - Apple Support

Best of Luck to You!

No.

Prior to this issue, when was the last time your Pencil was charged up and used?

IF your Pencil was left laying around unused for ANY prolonged period of time without being charged up and ready to use, then your Pencil battery may have failed and your Pencil may be dead.

I have the same issue after updating to 16.5.1 (c)

tried reset few times but no luck

pencil was working fine before the update