The Problem
We noticed something strange in our 3.3.0-7 live system. An author has made a new submission (in OJS 3.3.0-7) which immediately ended up under “Archived” and flagged as “declined”. Our editor in charge handling new submissions wrote me that the submission was declined even before she added herself. However, I cannot find any event log (see screenshot attached).
Debugging
DB: I have tried to analyze the DB but cannot find a clue. The submission has submission_progress = 0, stage_id = 1 (so far so good) and status = 4 (declined). The event_log database gives me exactly what the UX shows (all fine). email_log correctly contains the submission acknowledgement.
Only this one? We have only migrated one week ago. All other submissions (about 10) look absolutely fine ended up in “Unassigned” (all fine).
Additional idea: One thought I have is that something could go wrong when the user removes his author role and adds it again (even if this is disconnected). Tested on a test system, that is not causing it.
Any more ideas?
I am running out of ideas to track that down nor have I any idea what could cause it? Cosmic background radiation and bit-flips? 
If anyone has an idea what I could analyze in addition it would help me a lot!
Thanks in advance,
Reto