Adding Patch
I'll try and do my best to explain this.
When you create a new field group layout it sets the format type to layout_region. The problem is there is no format type called Layout Region. So it sets the field to the first item in the list. In my case it's tabs. You can see in the screenshot below that it's not draggable, but the layout is incorrect.
The next time you save it will set the region to be the tabs format and it will be draggable again.
My solution is to create a new FieldGroupFormatter called Layout Region. This will make it so the default formatter after creating a new field group layout will be Layout Region and not tabs. Then when you save it will stick. The patch is attached.
This does bring up the question of why does this module have a FieldGroupFormatter called Default. Maybe this is what was supposed to be used for the regions, but I think Layout Region makes more sense.
I'm running into big issues when you add a group element like you did. It changes the format from layout_region to something else. It don't think it has anything to do with this issue, but a problem when it reorders the items when you insert a new one. I'm not sure if that issue is with the field_group module or this module.
I'm attaching another patch that will only disable items that have their format set to layout_region. This will at least guarantee we won't affect other field group types.
Yup just ran into this. Sorry about that. Here is a new patch that seems to be working now. I tested adding a fieldset and a layout.
Attaching the patch. FYI this doesn't fix 🐛 Error when changing field groups from tabs to layouts Active . Although they both error out because a layout isn't selected.
redndahead → created an issue.
Attached is a patch that seems to fix this issue. It checks the parent wrapper and if it's format type is layouts type it will disable dragging. I have tested it under tabs and with nesting layouts.
redndahead → created an issue.