Hi I think you will find it is an Android change not a Fairphone one. Fairphone use the stock Android OS currently.
Rooting the phone:
EDIT: This is not advice to do so
Further I can find no app that does allow the alarm to work even when rooted. Sorry a bit of a wild goose chase.
First you will have to unlock the bootloader then root.
- It’s all a bit of a chore and unlocking the bootloader will wipe any personal data, so be sure to back up contacts and any images.
- If you have an SD card be sure to format it as portable