I’m not having that issue. Is is only facebook all every website on your computer or phone? If it is every site then you probably have your settings on night mode or energy saving.

Facebook has a dark mode and a light mode. The light mode has a white background, the dark mode has a dark background. I am using the dark mode which I find to be less glaring and more easy on the eyes especially if I’m in a dark room. Is it possible you are in the dark mode?

Dark mode would have white lettering right? Mine is still black on both devices and I didn’t change modes. Also, it’s only when I go into groups.