I have a hybrid app that worked perfectly in every test environment, and a previous version works perfectly in production. The test environments are designed to mimic production exactly, and they have been in use for many release cycles. Yet installing the beta using Testflight (overwriting the old production version) causes problems. No crashes, just getting stuck somewhere in the Javascript. We suppress error messages in production, so I'm not sure what's causing the error yet.
Without going into details on the app, are there differences between an iOS beta app and a proper production app? Clearly the underlying app is the same, and the ID is the same. Does Apple distinguish the beta in any way? Does Testflight do anything that might make a beta app behave different in any way? Even if it's a subtle change in the certificate or the way libraries might behave, this could be relevant to debugging the problem.