We're also seeing this. It popped up on our radar on June 7 and quickly became our top crash, both in our application and in applications that use our framework. The crash occurred outside of our release cycle and affects iOS 14 versions before 14.5.
https://twitter.com/steipete/status/1402874404187615232?s=21
I just filed FB9158935 with details and crash reports attached. I hope that helps.