Here. I will herp you!
OMG shantung and grenadine and awsm repp stripe? score
Ah yes, that happens sometimes when the stitching of the buttonhole is very tight, making it too stiff. More likely to happen with lighter fabrics, probably. That jacket sure looks like a 3r2 to me. Perhaps that buttonhole will loosen up a bit over time, is it a new jacket?