HRHD SR's not consistently auto assigning to our Tier1

Summary

Issues where SR's are not consistently auto-assigning.

Content

We are periodically running into an issue where SRs did not auto assign to Tier 1.  This doesn’t seem to have anything to do with people’s queues being full as they should sit at Tier 1 until they get assigned to an agent.  You can see from the images below there are a lot of SRs after the "unassigned ones" that were assigned to Tier 1. Has anyone else seen anything like this before? We believe we have everything configured correctly because it seems to work correctly MOST of the time. 

Thoughts?