Right, so running through Beyond the Rift EE I started seeing blue shields.
Blue shields are my arch-nemesis and as a rule I never see them since drow content is part of the focus of my current build.
Boom. So, there is it 3 + 54 = 57 failure.
Pre U22, to the best of my knowledge since I haven't played much in recent months, 54 was the cutoff for no-fail on everything but Drow Priestesses and Orange Names.
Incidentally this is the greatest travesty ever since it affects my build.