Dark/Light theme switch toggle resetting on overlay.

Hello, so I recently created a toggle switch that is on an overlay. This switch functions properly and works to toggle my screens modes from light/dark. however when the overlay closes, the switch toggle resets.                

For example: I am on a light theme > opens overlay > toggles to dark theme (it works) > switch changes to toggled > closes overlay > reopens overlay > switch resets to non toggled. 

as you can see this messes with the point of the toggle, every time I open the overlay after toggling to dark theme, I'm having to toggle twice to change to light theme, instead of it being fluid.
 
Does anyone have a fix for this?