Because my FP is rooted, I couldn’t install the update right away.
Couldn't update, installation problem
The problem is that the boot partition gets modified when you root your phone and this prevents the OTA package from installing. It’s described well on Quora.
This is how I was able to install the update:
Return to stock boot.img
- Get current build number →
Settings -> About phone
- Download stock boot.img →
(replace 091 with your current build number)
- Reboot to bootloader →
adb reboot bootloader
- Flash stock boot.img →
fastboot flash /path/to/boot.img
Install OTA update
Install update normally