Hi,
When you add a translate string to tag it will store the translated value under jcr:title.{language}
Ex: jcr:title.fr for french locale
The language string can be updated by modifying languages property under /content/cq:tags
When adding the tag to a page it will show only EN tag and based on the language of the page it will load the title if present corresponding to that language otherwise fallback to en.
language specific value:
Languages under /content/cq:tags
When searching for tag it will make an ajax call with search term English and I think it only searches for property jcr:title under /content/cq:tags
/mnt/overlay/cq/gui/content/coral/common/form/tagfield/suggestion.0.10.html?root=&query=Chines&_=1620964882874
You can debug the query and related code for more details
Hope this helps !