Hi Saquib,
The Show/Hide extension doesn't remove the input from the edit screen. It only toggles the input using CSS. That means both the inputs are there and that makes the browser users the latest value to send to PHP.
In this case, I suggest you use the Include/Exclude extension. This extension works similar to the Show/Hide, but it removes the input completely from the screen (if it's not included).
The other way is using different ID and then you can add a simple condition in the frontend to get the correct meta value.
Hope that helps.