Under Site Collection Administration -> Site Collection Audit Settings, I can enable events to audit, click OK. Then I go make changes; update a list item, delete a document, check out an item. I can then go to Audit Log Reports and run a report, say for Deletion, and I will have an Excel file saved in a Library where I can see listed the recent deletion/changes I made.
So everything seems to be working. But, after a nominal amount of time (seems to be under 30 minutes) if I return to view Site Collection Audit Settings, all the check events have become disabled (unchecked), but the Audit log trimming settings stay as set.
Running new reports don't show new entries for what I had selected to be audited. This happens for several Site Collections I've tested.
How do I get these Audit settings to stick?