This may be a known issue, but I didn't see it in the bugs list on canny.
Using
/above
or
/below
doesn't remove the
/above
or
/below
text (or fragment of those commands the autocomplete is matched before the whole word of
above
or
below
is entered).
Screenshots:
  1. After invoking "Add task above" with
    /abo⏎
  2. After invoking "Add task below" with
    /bel⏎