Show Friends inconsistency


Sometimes when I call the Twitter API for a list of friends, like this:
I get a list of friends, then I can call it again with a cursor:
and I get no results, because that cursor is the most recent friend

BUT, for some users, when I call to get the list of friends:
then call passing the most recent friend as the cursor:

I get a list with one id:
“ids”: [
which was the first user that this user followed.
Why does this inconsistency exist?