When using the "select advanced" field and "MB blocks" extension the display appears to be off. The value of the select field overlaps the "close" icon and it can be really hard for a user to see that they can remove a single item. I will provide a screenshot in a followup post to this.
It looks like it's a conflict between plugins using different versions of Select2 library. I have found this post https://github.com/Yoast/wordpress-seo/issues/17681 and it looks like Yoast SEO made an update and it's caused conflicts with people and their meta fields. Unfortunately, Yoast SEO is such a widely used plugin, I don't know if they are going to fix it or ask other plugin developers to update their Select 2 libraries to be compatible. It appears the library version they are using is placing the x is an absolute position from the CSS so it then overlays the text in the select bubble.