@ex @Charfuhrer It is not from MRF this time. One mention is for account on eientei.org, the other is for account on pleroma.eientei.org, which eientei has migrated from over a year ago. You can also technically mention the same account multiple times; beyond forcing mentions when those are omitted in a post body there should be no alterations on server side. But I still don't see a plausible explanation to how that extra mentioned appeared, even if you mentioned manually, you'd had to type out full @ + Charfuhrer@pleroma.eientei.org on pleroma-fe and soapbox versions, as pleroma subdomain does not seem to enter suggestions on either of those. Have you used some different client?