Consider following code:

var b = 10;   // << breakpoint 1
var a = bind b; //  << breakpoint 2
b = 13;  // << breakpoint 3

println(a);  // << breakpoint 4

1. when stopped on breakpoint 1, +Script node is visible
2. breakpoint 2 won't be triggered (at least for now) due to another issue
3. when stopped on 3 or 4, +Script node is not visible

apparently the difference is that in the first case the context is Main$Script (non-static context) and in the second case it is just Main.javafx$run (static context). The (java) debugger distinguish between the cases and passes javafx debugger information which javafx debugger resolves incorrectly.