@伪位蔚蠂慰位蠀蟿 A recent one could have received -2 votes and been removed while
better suggestions did not get +4 and so they remain until they hit -2 or +4. See:
meta.stackexchange.com/help/privileges/suggest-tag-synonyms - You could try asking a mod in chat or post on the site's per-site-meta a discussion explaining why you think it's necessary (hopefully drawing a tiny number of people to notice, which is hard to do on some sites). See my link above, the related questions, and