Player Upgrade Screen - Button Upgrades keep resetting!

Hi guys,

I have a small issue. I have an Upgrade Scene which contains the Canvas of Buttons for player upgrades. For now, I only have upgrades to player's movement speed. Player will enter the Upgrade Scene at the end of the stage.

However, every time I reached the end and it loads the Upgrade Scene, buttons for the upgrade are reset. There 3 buttons. I've already pressed 2 buttons. When I go to the Upgrade Scene again, it should have left with 1 upgrade button left to press. Instead all 3 buttons are available to press again.

My upgrade codes for the buttons are working and the upgrades are implemented. Its just that I could upgrade again. That should not be the case. I think its the issue of loading a scene and how to make the buttons remain pressed.

How do I solve this problem? I appreciate your time for reading this. Thank you.