How to apply left hand side of parent in indesign to individual page after turning off facing pages?

Yes, so in your original post you meant that only the right page of the Master Spread is applied to your "regular" pages, right?

That's normal. As you can see at the top of your screenshot, when Master Is a single page - it's located on the right side of the spread / represents right page - not left. 

So, when you are applying Master to a spread - in your case, single page spread - right page of the Master is applied. 

You just need to create a single page Master. 

Or are you looking for a solution to apply your Masters to every 2nd page? Left to 2,4,6,... and right to 1,3,5,...?