I hope you have already solved the issue, but I still want to share my experience. I started using Firestick not long ago, and I faced some problems installing kodi addons. When one of the chosen addons didn't work, I surfed the Internet and found a good article Why Is My Kodi Not Working? Common Problems and Fixes - Fire Stick Tricks that provided me with the possible reasons of the problem and explained how to fix it. I was lucky to do this job without help. Now I follow this info as a guide every time kodi doesn't work. Hopefully, someone will also find it useful!