SEO Image Optimizer Wizard

After using this app for nearly two years, and initially leaving a positive review, something about this app has changed and is now causing me problems. When optimising any images with a light to white part to it, e.g. a white square on a black and white checkered board, the white is being removed as if I have used a background remover. In some cases a different coloured background is also being added. If something has changed, they need to change it back because I can now no longer use this app and would advise others to be wary of light to white images.