The Fill Bug

I just wanted to bring to light an issue I've been receiving in my games and wanting to see if anyone else experiences them:

I know how frustrating it can be to be autofilled so I started putting fill as my secondary role. Recently tho, I've been getting a lot of players who complain how they are still getting autofilled into roles they don't want. I'm putting fill as my secondary and still getting my primary so I don't understand how this can happen multiple times.