Separately bold title font

Add this css in your custom css field –

.wpsm_nav-tabs > li > a{
  font-weight: 900 !important;
}

Add this css in your plugin custom css field.

try it and then let me know.

Thanks

Can you share me your tab page url?

Thanks

You will need to update tab title font size.

Try to delete plugin and reinstall it again from WordPress.

Strange,

Can you provide me screenshot of your browser console error?

Thanks