Every once in a while, Chrome will render perfectly valid HTML/CSS incorrectly or not at all. Digging in through the DOM inspector is often enough to get it to realize the
Below css works for me on IE 11 and Edge, no JS needed. scaleY(1) does the trick here. Seems the simplest solution.
scaleY(1)
.box { max-height: 360px; transition: all 0.3s ease-out; transform: scaleY(1); } .box.collapse { max-height: 0; }