Unfortunately, I could not find any troubleshooting for this. But I'll be happy to post it in the community, maybe a user can help you.

Unfortunately, we do not have this model in our range for your iPad Pro 12.9 inch 4th Gen. We only have the keyboards from Apple and Zagg in our range, with the CH layout: https://www.digitec.ch/de/search?filter=t_pt%3D2043%2Ct_13%3D287%2Ct_8886%3D579221&q=iPad+Pro+12.9

According to the manufacturer, this keyboard is unfortunately not compatible with the aforementioned MacBook Air.

The Apple Pencil is not attached to the case, but to the iPad. This is done with a magnet, as this magnet is not the strongest, it can happen that the pencil flies off. Unfortunately, you can't do it any other way because the Apple Pencil 2nd generation charges itself via this magnet. If you have the Apple Pencil 1st generation, this is clear because it does not have a magnet. I hope I was able to help. LG

This keyboard is compatible with the following models: Pro 11" / 1st gen. (A1980, A2013, A1934, A1979), 2nd gen. (A2228, A2068, A2230, A2231) and 3rd gen. (A2377, A2459, A2301, A2460). Unfortunately it is not compatible with the iPad Air.