Why does the tailsiter motors stop?

I am testing the TAILSIT mode Plane:Quad Motor Tailsitter,four motors on a wing, copter/plane mode transitions. The VTOL mode takes off normally, but the four motors stop running immediately after switching to AUTO mode:

Q_TAILSIT_MOTMX,Should I set this parameter?
Here is my parameter table:
1.param (20.7 KB)