If you updating plugins, it is possible that there is any plugin conflict with one of the new versions of the updated plugins.
I suppose you, that temporarily deactivate all of your updated plugins or all of your plugins except WooCommerce and WooCommerce Custom tabs, and check whether the problem is disappear.
If so, please activate the plugins step by step, and check the tab after each activation.
This way you can find which plugin conflicts with WooCommerce Custom Tabs.
You can also try temporarily switch to another theme, if you updated your theme.
Please let us know what is the result of this procedure, and if you find any plugin or theme that is in conflict with our plugin.