Bus refusing to connect to anything on only one subsheet

It’s always pretty hard to judge a problem from only a picture.
The best way to get help is to add the problematic project (always attach the complete archived project from Kicad main manager–>File–>archive project).

As you are currently a new user it could be that you are not enabled to attach something. So you need to read some more threads until you become a “basic user” (see New Member Information).

At the end I try to guess something: do you have really used the “unfold from bus”-command to draw the connection between your nets and the bus?