My support request got a generic answer aimed at someone losing out because the placed bid was done during a busy time and it missed the end of auction time by a few seconds, with the suggestion to increase the lead time.
That is an interesting problem that is outside the control of AS, but it's not the one this thread is about.
This thread is about having a snipe request in the Active list hours after the auction ended, and AS not executing the requested bid on our behalf. And no explanation and no comment about this happening anywhere on the site.
I've pushed back to get a better answer and the problem is moving up the chain.
When a answer comes back I'll share it here in this thread.
While writing up the push-back I thought of a scenario that explains having a missed snipe request remaining in the active list hours after the auction ended.
It's the simple case of the AS system getting bogged down and not keeping up with the ticking clock. When it comes time to get the set of snipe requests coming due next, the main sniping engine should only consider requests for auctions having ending times in the future (to avoid wasting time handling those with ending times that have passed, since they have no chance to succeed). So, if something happens that causes a lost period of processing time, then requests for lots with ending times in the past are not handled.
Another process that runs occasionally with a low priority can run through active lists looking for requests that aren't handled by the main request processing engine (because of ending times in the past, and other reasons) and this other process then puts the request into the Ended list with the "did not win" label.
This is a consistent scenario with what was seen and with how working systems are designed. I don't know if it is the explanation for the particular case of this thread.
If it is, then the pitch will be isn't that how you'd want it to be - don't you want a system taking care of your live requests and not have the system wasting any resources for requests having no chance to succeed. When things get tight, take care of the living and let the dead alone.