Singleplayer. Hell. In Act 1 town right now. I have 300 lightning res during this picture so it should be maxed.
If it also matters, I think I made this character when 2.0.0 came out.
I also tested by adding a Perfect Amber to my body armor (+1 Max Lightning res) and I reached 76 Lightning Resistance, so this could be an actual issue with Eye of the Storm or incorrect info for Eye of the Storm.
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EDIT: Ooops I'm stupid. Yeah I need to be casting to get the bonus