The best part will be to re-pro the bug/issue raised either on the real device or the emulator. AFA you can not re-pro the issue it will be hard to debug the same. Therefore I would recommend that you ask the complete details about the issue, like :
1. The targeted device
2. Steps to reproduce
3. Frequency of the issue to re-pro
I all the above or the more details can be found, the debugging the issue will be simpler. Then you can start to look into some direction which would help more to find and fix the same.
Check and revert.