it might be the /kbin core, not your site you're on.
if you mention someone at your instance here i also prob would see a "full url" (as long it's not the same instance we are on, yes even if it's kbin based)
linking magazines is even more broken.
if i link a kbin social magazine, its not even gonna show, if i do mention a magazine on another instance here on kbin.social it does shorten and link to it, while the ppl over there just see the "full url" of my mention vice versa :,D