She has also had problems reading Deathstroke (the Jobber Aura, eet ees strong....), but that one gets discounted because she has done just fine reading him before.
....at least the writer tried to give a sensible reason.
Didn't she have issues with "reading" Monsieur Mallah Gorillaness at first?
Frankly, her having issues reading Mallah would work far better for me than Deathstroke - nonhuman body - and I'd be cool with it if she didn't already have a career of reading weird stuff (multiple shapeshifters, space aliens, etc....:).
To be fair, there was also a cyborg she couldn't read at first, because the author wanted her to get shot. It totally ignored the fact that she's a bullet timer as well (and this was under Damon Scott), and that the cyborg, aside from his eye and hand, was otherwise flesh.
Basically Scott wanted her to get shot so she and Tim could have a chat about her background.
....she kicked this cyborg around like a toy, later. Same issue. Sighs.
PIS, PIS, put our knowledge to the test....