We had an issue with recurring alert subscriptions disappearing after approx. two weeks, so we started calling the SetAlert service every once in a while with 0 as date_start and date_end. But now we receive duplicate flight alerts. I guess the SaveAlert service can’t be treated as an upsert service? We experienced a similar issue where we had to re-register our callback endpoint after two weeks.
Is there an expiration date associated to an alert subscription (and registered webhook endpoint)?