Unexpected forward transition during RTL

Hello, all

I tested a tailsitter drone today with PX4 dual rotor firmware v1.8.2. In the middle of flying in mission mode, I switched to RTL. When the aircraft reached the home position, it transitioned to multi-copter mode (as expected) then, somehow, it switched back to fixed-wing mode again whereas the vehicle_global_position is healthy, and the aircraft is not in failsafe mode. My question is why did the drone transition back to fixed-wing mode again after it had already transitioned to multi-copter mode during RTL?

My expectation is When switching to RTL mode. The aircraft would fly back home in FW mode then transition back to MC mode and land.

Here’s the log: https://logs.px4.io/plot_app?log=5b0a9781-4648-41d9-bd04-e246819571ea