In nestable elements, if we delete the items using the delete button (image below), it will close the element settings. It seems that this bug was created in version 1.8.6.
I had a question. Is there a specific reason why the nestable tabs element doesn’t have an items section? Other nestable elements have this section, but nestable tabs do not. While it can be very useful.
I was able to reproduce this small UX issue and added it to our bug tracker.
The structure for the tab element is different from the other ones. While the accordion and the slider have a “one item structure” a tab is split into multiple elements (title and pane / content). So it is not possible to reflect the tabs in the element settings like we do it for the other elements.