Then the answer is, as with the other case, data dependency. If you wire a value out of your sequence frame into the while loop you've established a data dependency for the while loop since the while loop needs to know what the value of that wire is before it can execute, and the value is not set until the sequence frame ends.
Since your while loop houses an event structure, generate an event at the end of your sequence frame to stop this parallel loop. A crude solution: Wire a True value to the "Value (Signaling)" property of the "Stop" control, and change the event case from "Mouse Up" to "Value Change". You should make sure to initialize the "Stop" button to False at the start of your program, and to change the mechanical action to "Switch When Released":
