Updating CSS classes in production doesnt show changes
Heres a picture of the select2 boxes. You can see the UL html was added, and the select fields have the hidden property, but are still showing
Not sure it's related to this specific thing, but Jumpstart Pro uses PurgeCSS in production and staging to strip out any unused CSS to make the files as fast as possible. If you didn't have the class referenced in the locations it looks, it can strip out the class on accident when compiling.
You can tweak the whitelist for that in postcss.config.js in the repo and add your own classes to the whitelists so they don't get ignored. It also supports regex so you can use that to whitelist a set of classes too.