Sooo, the fix? DO NOT INSTALL FreeMake… I had the utility installed ages ago, before working in UE, but somehow it kicked into high gear and messed up a part of the unreal engine in ways I cannot even phantom.
Spent the last week trying to figure out what the cause was, and finally ESET called out on this being malware/pup and got rid of it. I’m leaving this here if anyone ever has the same issue, I hope I can save them countless hours trying to wrap their head around the it…