I've noticed that as well -- no matter how engaged someone is, if there is a screen that they can see but others can't then it is an information imbalance that is disruptive to the normal flow of conversation. It's like hearing half a phone conversation -- your brain works overtime trying to reconstruct the part it can't see. And it makes some sense; when I am talking to a person and they keep glancing at their laptop, phone, or watch it's exceedingly off-putting and they seem disengaged even in cases when other evidence indicates they are paying attention.

I've similarly noticed that interacting with someone wearing a bluetooth headset or smart glasses is off-putting no matter how much they indicate they are paying attention and not watching or listening to something I can't see.

Like you, I prefer to type my notes. I've found that angling the screen down so that I can't see it either and then maintaining normal eye contact with everyone makes the problem mostly go away. Possibly because I'm not constantly breaking eye contact to furtively glance at a glowing screen that they can't see. Or possibly because I wasn't paying as much attention as I felt like I was -- there is some research that indicates that people who can see a screen or TV while they are accomplishing a task often significantly underestimate how much time they spent looking at it and how much it negatively impacted their task performance.