That's the problem that I think many people are having. They pause the game as soon as the chief points out the collectible, which prevents it from appearing. In VV3, collectibles don't appear (or disappear) while the game is paused. Since it can take up to a minute (maybe a bit more) for the collectible to appear, the act of pausing the game actually prevents the rare collectible from appearing at all. When the chief "does his thing" you should not pause the game until you've searched for at least a minute without finding it.
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Barbara
Unicorn
Last Day of Work