Having the same issue.
Here is screenshot one, when I entered ToV yesterday (yes I still need more defense skillups):
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And then here is screenshot two, from later on in the exact same raid on the same day:
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Difference was I died and loaded back into the same zone after res.
I have noticed this apply to my instrument skills as well, as well as a few others. I'm pretty sure I've seen Defense cap out at 200 on a few occasions instead of 215 as well, which is obviously even worse. 215 is the most common number it's stuck at.