I have noticed the same issue on https://vomax.com.au/documentation/ since updating WordPress recently. It works but caused the client to think it was broken.
In my case, the Document Types field exhibited the issue while the Document Tags field did not. Importantly, the latter had a search field within and the former didn’t. The presence of the search field seems to be determined by the number of terms so I worked around the issue by using the filter to always show the search field within the dropdown. This is documented on the plugin home page on www.ads-software.com:
function change_minsearch_value($min_search){
//always show search
return 1;
}
add_filter('beautiful_filters_selec2_minsearch', 'change_minsearch_value');
From: https://www.ads-software.com/plugins/beautiful-taxonomy-filters/
It would be nice to have the original issue resolved but this workaround may help in the mean time.
