[Bug] VTOL Fails to Switch to MC Mode During RTL After Losing Manual Control Signal

[liu12344321]

Describe the bug

I have set NAV_FORCE_VT to enable and RTL_DESCEND_ALT to 30m. My understanding is that in the landing mode, the VTOL should descend in fixed-wing mode while circling until reaching this altitude (30m), and then switch to multirotor mode for a vertical descent as it approaches the landing point. However, when the VTOL loses the RC signal, it initiates RTL and begins descending, but instead of switching to multirotor mode as expected, it continues to land in fixed-wing mode. This results in an improper landing behavior.
altitude diagram and motors diagram as below, which may show drone didnt switch to mc in landing mode , after the drone touch the ground, failsafe actived, Quad-chute triggered.

To Reproduce

1. Drone switched on
2. Uploaded mission and execute it.( drone took off)
3. transition to fw mode.
4. pause the mission and let drone loiter
5. lose manual control
6. cause of failsafe drone enters RTL mode
7. drone performs a hard landing in fixed-wing mode

Expected behavior

Drone should always land as a multicopter.

Screenshot / Media

No response

Flight Log

https://review.px4.io/plot_app?log=950f40bb-68d9-4c6c-a634-98e6b1f511b9

Software Version

v1.15.1

Flight controller

Holybro 6c mini

Vehicle type

Hybrid VTOL

How are the different components wired up (including port information)

No response

Additional context

No response