What controls are in your cluster?
If you have buttons, check the mechanical action: latch when pressed or latch when released will return to the default position after the control is read. Switch when released (or pressed) won't return to default. Right-click on the button control and select Mechanical action.
If you're using numerics, check the data range and the action if value is out of range: if your range is too small and the control is set to Coerce when out of range, you could see the default value instead of the value you entered. Right-click on the numeric control and select Data range.
If this doesn't help, post your vi.