[2020] [Bug?] - Cannot progress beyond Stage 2 of Field Research: Gunner.

I have googled around, and am aware that back in the day you needed to light him on fire and do the Air and Space Mission on Hard, and there was other stuff (capturing Supply Points and what have you).

Evidently they made these Field Researches easier at some point recently, as all it says I need to do is "Defeat Lt. Kelly in Air & Space Museum on Normal+"

I've done this multiple times now, all the way up to Challenging. No dice.

If I need to do something else besides what the UI is telling me I need to do...that's pretty ****ty. But I'm at a loss here. I've done these runs solo thus far, as no one is matchmaking for this mission these days.

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I'm on PC, in World Tier 5 if any of that's relevant.