A Singing Frog
A Singing Frog is that annoying bug that disappears before you can fix it. It’s like the tech world’s version of a ghost that only shows up when you’re not looking.
The printer worked fine when I tested it, but it stopped when I showed the client.
The app glitched every time I used it, but it fixed itself the day I brought it to the tech support guy.
The mysterious noise in my office only happened when no one was around.