@doskel general anxiety, kinda! i need to be really comfortable with a person to accept a direct call. even if the alternative is literally just hopping into a one-to-one voice chat on discord, i'd still lean for that over a direct call. it's pretty weird and irrational for sure.
specifically on phone: i'm generally uncomfortable calling friends when i'm not at my proper setup at home (i can't rely on voice quality, and i've been overstimmed by awful background noise and the like before)