Had a thing recently where something had been quietly failing for a while and I only found out because the client mentioned it in passing. Not dramatic, nothing on fire, just wrong for longer than I'd like to admit.
What got me is that the automation didn't error. It ran. It just did the wrong thing, cheerfully, every time.
Anyone else had one of these? Curious how long yours ran before someone noticed, and what tipped you off in the end.