I do not have much experience or knowledge of cooking, but I've slowly been learning.
Today I followed this recipe: Beef Stir-Fry. Besides some vegetable substitutions, I had a bit more meat and doubled the sauce ingredients. For the acid, I used lime juice for the first half (2 tablespoons), but ran out, so I used rice vinegar for the other two tablespoons.
After the meat had been cooked, I removed it and reduced the sauce. Around that time I noticed that the patina in the direct middle of the wok had been stripped.
The seasoning on this wok was pretty good (as you can see around the edges of the center), and just this week I had made another stir-fry in it that had rice vinegar in the sauce. Since I had no issues with that, I figured it'd be OK to use lime juice and rice vinegar in this recipe.
The two main differences between what I did earlier and just now was A) earlier I used canola oil instead of olive oil and B) earlier I added the sauce last instead of first.
My gut is telling me that when I reduced the sauce, the acid stripped away the seasoning, which didn't happen before because of either temperature or length of time. However, I just am not certain.
I'm mostly interested in how I can avoid this in the future, and what to do now with the wok. Should I scrape off the rest of the patina and start over? Or just continue to cook with it normally (and more carefully) to rebuild it?