Hello, bvg tickets app is not working on brand new FP6. Tried removing app and downloading again without success. If anyone as any tips… 
Welcome to the community forum!
Which operating system do you use, /e/OS (Android by Murena), or Fairphone stock Android?
Which software version are you on?
What does “not working” mean? Does not start? Shows some error? Does not do some functionality inside the app?
@Audrey2 A few years ago I had many problems with the bvg app with /e/OS. Sometimes with an update it just wouldn’t work, so I would have to uninstall the app and reinstall an older version and avoid updating the app for as long as possible. I eventually had enough, and installed the VBB Bus & Bahn app. I’ve found it to be almost always very good. I know this won’t help if you’ve already bought and still have valid tickets in the bvg app though.