I recorded a video

https://ufile.io/cz9gw634

After testing, it is a bug
In the BIAB main program, use loop Pak 1 & 2 to have lead in, and there is a prepared sound lead-in at the beginning
However, when loop Pak 1 & 2 is used in BB VST, although lead-in is checked, there is no sound.

Have you got that Loop ?

You can load Click 110bpm.wav in Audio + track

I have.

The key is that the BIAB main program is normal.
However, there is no lead-in sound in BB VST

There are lead-in count-in notes in the RealDrums but you are using drum loops there is no count-in.
Can you set the count-in in Studio One ?

But in the BIAB main program, I also use loop style.
It was ready to shoot at the beginning.
The key is not to prepare for shooting, but the generated sound is humanized and misaligned. I want to test the preparation for shooting alignment.
It's like I have to check lead in and ending in order to have no gap

You can Drag "C7" into track to get lead-in

That's the only way. This is not a problem compared with that gap problem