Uncaught Error: No select2/compat/dropdownCss

Hello,
I see this error in console when I try to edit an ACF field in field groups.
When Ultimate Member is deactivated I can edit the fields.
This is what an ACF Plugin Support rep said:
It looks like you’re encountering a JavaScript error related to the “Select2” script, which is used by ACF and many other plugins to create enhanced selection boxes. The error No select2/compat/dropdownCss typically occurs when another plugin or your theme loads an incompatible or different version of the Select2 script on the same page, causing a conflict.

Is this a problem that could be fixed in Ultimate Member?

This is the complete console error:

Uncaught Error: No select2/compat/dropdownCss
at callDep (select2.js?ver=2.10.2:225:19)
at req (select2.js?ver=2.10.2:394:20)
at select2.js?ver=2.10.2:200:24
at Defaults.apply (select2.js?ver=2.10.2:4703:27)
at new Options (select2.js?ver=2.10.2:4941:29)
at new Select2 (select2.js?ver=2.10.2:5068:20)
at HTMLSelectElement. (select2.js?ver=2.10.2:5689:26)
at ce.each (load-scripts.php?c=0&load%5Bchunk_0%5D=jquery-core,jquery-migrate,utils,wp-dom-ready,wp-hooks&ver=6.8.1:2:3129)
at e..each (load-scripts.php?c=0&load%5Bchunk_0%5D=jquery-core,jquery-migrate,utils,wp-dom-ready,wp-hooks&ver=6.8.1:2:1594)
at $.fn.select2 (select2.js?ver=2.10.2:5686:14)

The page I need help with: [log in to see the link]