If you find that your Pencil which was working fine with your iPad Pro suddenly won't access the screen/apps, check to see that the tip is fully screwed in. It's threaded to the outer Pencil sleeve so you can replace tips when necessary. I didn't realize this and had noted that my Pencil tip was a bit wobbly. After screwing it on completely, now it's stationary and my connectivity issue is no more. Such a simple thing and of course if it's not fully making a connection, you'll have contact issues. I had been using my Pencil with it working just fine, and over the last few days was going crazy when while bluetooth still said it was connected, I would find I could no long access anything when I could just minutes before. Tried various things with powering on and off, redoing bluetooth connection in settings, etc. with no luck. Didn't see anything here, so looked in on the Apple Support Pencil forums and read a thread that people found that their issue was resolved simply by making sure their Pencil tip was screwed in all the way. Thought I'd pass the info on.