Passengers disappeared at interchange stop

[796B]

The situation is like:

Let there be 100 passengers waiting at stop A, their final destination is stop C.

They must take route 1 to reach the interchange stop B, and change to route 2 to reach stop C.

When they have just arrived at stop B, they are supposed to wait for the buses of route 2 there, but they disappeared! None of them get on route 2 to reach stop C.

I have checked that there are no other routes serving both stop B and stop C.

What's happening??? How could I solve this problem?

Could anyone help?!

[Ters]

Which version of Simutrans are you using?