Same issue, although only versions < iOS 15.0 seem to be affected.

Not sure if that error code catches all errors of that type. As a quick fix were now showing an activity indicator and are postponing any error messages for +- 20 secs. This gives us time to keep the error message away from the user, when in that time a purchase was successful after all. Still not the best solution.

I'm experiencing this issue for at least a month now as well. I was watching this issue and hoping for a solution. In my case Firebase shows thousands of crashes related to CoreData or CoreFoundation on one of the following: "PFObjectIDFastHash64" "-[NSManagedObjectContextdisposeObjects:count:notifyParent:]" "CFBasicHashRemoveValue" It's only iOS 14 and although I don't know how reliable the data is, but the majority seems to be on iPhone. I'm not able to reproduce it and haven't heard any significant complaints from our helpdesk either.