Glowing white mushrooms on Mooshroom’s backs

From afar, the three mushrooms on the back of the mooshroom become pure white, and only revert back to normal when I get close to one, for some reason it affects every mooshroom in the area, even ones that are further away

It also seems to only happen while in first person, as third person doesn’t get the effect

I was using add-ons in the clip, but I checked if it still worked without any, and the bug still happens in a pure vanilla world