Issues with products

I’m having troubles changing images within my website. I just noticed that after I changed all of my images in my variations, that only 3/4 of them changed. The last 1/4 of them remain the same. I have even tried to just remove the image and save the product, but it remains the same. I have tried this for 3 different products with the same result. For some reason it will not change the variation images. Is there any reason why this would happen? Any help would be greatly appreciated. Thanks.