I have an instance of a person who was imported as a lead, their Unsub status went through System Flow Action, resetLeadEmailStatus, which changed them immediately to Unsub=True. Fair enough. 10 days later in their activity logged they are recorded as System Flow Action, updatePersonEmailStatus, Unsub changed to False. No other actions, no open email, no click on link, no change of list membership..
Can anyone explain why this would happen? I've spent a week learning everythign there is to know about Durable Unsubs, but this renders everything I thought I'd learnt invalid.