I verified that this bug affects the 1.6 dev tip as well.

If you have a session in the prearchive, and you go through the "Review and Archive" process, archiving will be blocked due to scans offending either the site or project import filter. However, if you simply click Archive > OK in the prearchive, the session archives without complaint.

This is bad for sure, but it's actually more of an edge case than it appears at first glance, because when DICOM is sent to the receiver, scans will be filtered out from even reaching the prearchive that are problems compared to the site filter. Additionally, if the project routes to a project in the prearchive, the project's filter will filter out offending scans as well. So, there's 2 main cases where I could see this being an issue:

Case 1: Edge case

1. DICOM is uploaded
2. While the DICOM is sitting in the prearchive in a project, either the site or project Series Import Filter changes
3. User archives the session, bypassing the filter

Case 2: More common case

1. DICOM is uploaded with project improperly set, so it shows up in Unassigned. Site import filter has already taken effect.
2. Session is moved to correct project, and archived. Since project filter did not activate on send, and it's bypassed now, the project-level filter never hits.