As Crazysob83 has said a few posts above mine; there's an issue with people planning to use a save from last week. They're currently 0/14, but are planning to start at say 7/14. If I was 2/14 I can't queue for their group, even though they will be starting further in the instance than I'm saved to.

If possible, you should make a player select which boss they start on when making a group, rather than using what they're saved to this week.

Alternatively, you could give us the ability to message a group leader so that we could ask them for an invite that way.