Images in posts too wide when “max image width” is set

Product Support
12

It means my forum have problem. But I have no find any problem. I try remove all plugin, Theme component and can not fix this error.

Now I must add this css in custom css to fix problem:

.d-editor-preview .image-wrapper img, .lightbox-wrapper img, .cooked img.d-lazyload {
    width: 100%;
    height: auto;
}