I'm on SDF's Mastodon instance, specifically social.sdf.org for members, and I am have issues with custom emoji from other instances as shown in the picture.
Hey, mod over at social.sdf.org here. I don't have permissions to fully administer the instance (and I don't think the other mod does, either), so you'll want to email the instance administrators ([email protected]) and let them know. Might be a software configuration issue.
Yeah I have the same issue, both in body texts and in usernames. I'm not 100% sure if this is just a Mastodon limitation or not, though (I primarily use a Sharkey instance).