OK, it will be very difficult to track down without a crash report. Do you get a crash report locally that you can manually symbolicate?
Another idea (although it might be a lot of effort): If you can build the app locally on your machine with a custom Expo SDK maybe you can try to use git bisect to find where the problem was introduced. For this you’d need to do something like clone GitHub - expo/react-native: A framework for building native apps with React. and then bisect between a version of the SDK that worked for you and the sdk-34.0.1 tag. This is not something I’ve done before with Expo, but I have used git bisect successfully for other things several times.