Light Function not working, please help.

So I’ve created a really simple light flicker material, I apply the light function to the light (which is stationary) and even tho the thumbnail of the material is flickering as intended, my lights do not change at all! I have tried this in a fresh project and it works just fine, which begs the question: how can I get this working in my main project as I’ve invested a massive amount of time into it already.