GPS LED Not Lighting Up
The i2c address of the LED on the Holybro GPS has changed creating a need for modified firmware.
When connected to QGroundControl it may have prompted you to "upgrade the firmware". This would roll back the fix for the GPS LED.
Confirm the firmware shows up in QGC as v1.11.3-0.2.3, this version has the LED fix. We will maintain this fix going forward, so any future firmware from ModalAI (Change Log) should work as well.
It's not obvious which of the GPS modules has the LED I2C address changed, but the LEDs are validated to be working prior to ship during normal flight test.
The latest ModalAI firmware as well as update procedures can be found here