can you post a few photos of how you mount the external peripherals? this is not your drone photos. if you are using this Hereflow both onboard sensors are facing the same direction. then your orientation should be down (25) using the CAN bus and not the serial bus. you have to mount an additional standalone rangefinder sensor forward for object avoidance.
RNGFND1_TYPE = 24 (DroneCAN)
RNGFND2_TYPE,20
https://ardupilot.org/copter/docs/common-hereflow.html#connection-to-autopilot
Remember to do the test to ensure it is working before further flying, example
if you experience height holding oscillating up and down with a rangefinder height sensor, try setting SURFTRAK_MODE,0.