If autopilot is booted when GPS_TYPE and GPS_TYPE2 = 1, autopilot does not find Here3 in CAN, but GPS2 with uart works ok.
If now GPS_TYPE is set to 9, both GPS’s start to work ok. This does not help though if autopilot is booted, because after that, only Here3 GPS is operating. In that state after autopilot boot GPS2 cannot be operated by any paramater change. Only way to make it work is to set both GPS_TYPE’s automatic=1, and rebooting.
It looks like after both GPS’s are working ok, the automatic type setting can be made active also for Here3 (gps1). This helps to keep GPS2 reachable after next reboot, but requires always the GPS_TYPE2 parameter temporary change to 9 = can-mode.
Here is link to same problem in Arducopter. Don’t know if it is fixed there or not. Suggested fix using BRD_BOOT_DELAY does not work.