I will just report and issue regarding on dragging and dropping the Field groups, because it is a bit hard to re order if there is a lot of field groups with a lot of custom field in it. also another issue that I found out, is when you drag and drop a field group that has a wysiwyg custom field, the wysiwyg will be hidden after the drag and drop. By the way, I am using Version 5.6.4.
I have attached a screen recording video, so you can see the issue in action. Please see the link below