I played with the gap, which initially didn’t appear to be all that different than others. What seemed different was that it was slightly overlapping an edge and so wouldn’t fall through the slot (or, when it did once when I was adjusting the gap, it wouldn’t come back up.) Upon further inspection, I found that it lacked the same springiness of other reeds. I took a close-up picture of the Reed, near its base, and it does appear to be fractured as compared to other functional reeds. I’d attach photos, but doesn’t seem it’s possible on this forum (correct me if I’m wrong.) I can also send photos by email if someone would be willing to take a look and provide their address.
Meantime, assuming I’m correct it is fractured, is this possible/manageable to repair? I live in Brazil, so unfortunately I suspect it won’t be doable here. But still… Crossing fingers.