On 3 occasions now in the past week for myself and on 1 occasion for my son while in my party, we have insta-died from one or two hits with basically full health and armor. 

Is it just me or is this a thing now? Maybe I'm crazy or maybe there's a bug introduced that causes these insta-kill moments when you're essentially full health and full shields???

I think there are certain super edge case scenarios that will instakill you that I'm not sure if are intentional or not.

For example in certain cases on the newest mission I've seen that if the Trygon gets you from the sand near enough to a rock on certain areas of the map you'll insta-down. I've only had this happen once, but it felt terrain/circumstantial related and it felt like it wasn't supposed to happen.

Or, there actually are very subtle and intentional insta-death cases, but something extremely specific and circumstantial bug wise with terrain or something still could be the case, hard to say.

Has that happened to you a lot in specific contexts? I really haven't seen it happening a lot, so that's odd.

I've noticed there are a lot of scenarios that nid snipers aren't showing during animations etc and you just get annihilated from no where. I have had a few deaths last few weeks from full health and no idea what happened.