(FIXED) As of version
14.0 of Safari on macOS, and release
114 of Safari Technology Preview, webkit can not transition the
flex-basis attribute alone, when applied to the
/* this does not work in Webkit! */ transition: flex-basis 0.3s ease;
This works fine in Chromium and Mozilla-based browsers.
To get this working in Webkit, you’ll currently have to use the
/* this works in Webkit */ transition: all 0.3s ease;
However, this can be potentially performance heavy, as all properties are being transitioned.
Webkit Bugzilla bug