That’s probably Missionplanner?
The bootloader that ships with the PH4-mini doesn’t differentiate it from the PH4, so the way Missionplanner decides which firmware to load doesn’t work properly.
If you update to the ArduPilot bootloader for it, it’ll select the right firmware. Or you can use the custom firmware option.
FYI for Copter, PH4-Mini isn’t on a Stable release. http://firmware.ardupilot.org/Copter/beta/PH4-mini/
No worries.
I quite like the PH4-Mini.
To see one in flight with ArduPilot, the mini-quad in this video: https://youtu.be/0s1ZBSB0tvM has one (no production on that vid, it’s just a flight record, but pretty cool nonetheless).
I had the same problem with my PH4 mini, i downloaded the same file for plane, and custom installed, and it now works well but no beeps on start up? is it suppose to beep on start up?