JS error when validation metabox without tabs

Problem
When Meta Box Tabs is active and you validate a metabox without tabs, validation causes a JavaScript error:

tabs.js?ver=1.1.7:12 Uncaught TypeError: Cannot read property 'panel' of undefined
    at showTab (tabs.js?ver=1.1.7:12)
    at HTMLFormElement.<anonymous> (tabs.js?ver=1.1.7:41)
    at HTMLDocument.dispatch (jquery.min.js?ver=3.5.1:2)
    at HTMLDocument.v.handle (jquery.min.js?ver=3.5.1:2)
    at Object.trigger (jquery.min.js?ver=3.5.1:2)
    at HTMLFormElement.<anonymous> (jquery.min.js?ver=3.5.1:2)
    at Function.each (jquery.min.js?ver=3.5.1:2)
    at s.fn.init.each (jquery.min.js?ver=3.5.1:2)
    at s.fn.init.trigger (jquery.min.js?ver=3.5.1:2)
    at validation.min.js?ver=5.3.9:18

Reproduction path

• Activate Meta Box Tabs
• Create a metabox without tabs with a required field
• Open the post type with the metabo, leave the required field empty and save the post