Hello,
Actually I don’t see problem with the tag that has the Georgian characters, for example, https://kiku.ge/product-tag/%e1%83%90%e1%83%9b%e1%83%a7%e1%83%94%e1%83%9c%e1%83%94%e1%83%91%e1%83%94%e1%83%9a%e1%83%98/ It does not display not found page http://prntscr.com/qfw70q Our support is able to help you with issues related strictly to theme options and issues. Changing of the permalinks and slugs is not theme option/theme issue.
Maybe ask you admin and try to make a redirect for the old site to the home page or to the shop page of the new site to allow users to search for the products they are interested in.
Regards
