Failure to Discover External Compass on Boot

I have a Matek H743-Mini flight controller and am attempting to interface with an LSM303D breakout board from Pimoroni over I2C. I’ve connected it as per the below wiring diagram, but it’s not showing in the Compass or HWID tabs in Mission Planner.

I ran the example i2c_scan.lua script, which consistently reports that an I2C connection is detected at address 0x1D (the address of the LSM303D). I assume this means the compass is in fact wired correctly and working. I’ve also double checked that the LSM303D is supported by ArduCopter.

Is there any reason the compass would be detected via script, but not register in ArduCopter’s list of compasses? Are there possibly some parameters I need to change? Do I need to somehow tell ArduPilot where to look for the compass?

I should note that there are two I2C busses on the H743-Mini. The compass is connected to the breakout bus (bus address = 1), not the onboard bus (bus address = 0). Maybe this has to do with my issue?

Thanks in advance for any assistance.