Here is a solution that is supported by all browsers and ie9+
1. Open the file …/wp-content/plugins/q2w3-fixed-widget/js/q2w3-fixed-widget.min.js
2. Search for
t.obj.css("width",o);
3. Replace both (it is twice in there!!) with
t.obj.each(function(){this.style.setProperty('width',o,'important');});
4. These changes are lost with a plugin update so I would recommend renaming the plugin folder “q2w3-fixed-widget” to something like “q2w3-fixed-widget-custom” (after renaming you will have to activate the plugin again).
What this does is adding an !important
to the element style width of all fixed widgets and thereby overwriting the divi widget style width: 100% !important;
You are welcome.