Each Embassy has different kind of backlogs. If the backlogs gets too big, they can't schedule anymore Interviews, resulting in answers like you got "No available date for interview". Abu Dhabi Embassy for example where
@lost-Yusuf case is at right now has reached DQ Nov, 2022 as of two/three weeks ago.
Always keep in mind, it's different for i730 since it is not a traditional VISA as it is for normal family reunification petitions. We are Follow-to-Join.
But it is a general direction. So your "DQ" is basically your "READY" Status. We need to wait for the backlogs to be resolved or get ahead in scheduling. Nothing else to do besides wait, sadly. Don't lose hope.