What does creative fatigue mean on Meta?

The two statuses are set by cost. Meta says it considers all recent exposures of the ad's image or video, including those from other campaigns from your Page, and also considers your ad's cost per result. When cost per result is more than ads you've run in the past, but less than twice as much, you see Creative limited. When cost per result is more than or equal to twice as much as ads you ran in the past, you see Creative fatigue.

Meta also warns in advance: if it predicts that creative fatigue may occur in the first seven days of your campaign, it says it will warn you before you publish your ad. Its recommendations include creating a new ad with a new image or video that is materially different from the original creative, and it notes that keeping your original ad active instead of pausing or turning it off may maximise results. It also suggests expanding your audience, or trying Advantage+ creative, which it says is only available for campaigns using the traffic or sales objectives with website destination.

Our reading, not Meta's: both statuses compare the ad's cost per result with your own past ads, not with other advertisers, so the same cost can trip the status in one account and not in another. Adding a new ad to your ad set is on Meta's list of significant edits, so following the first recommendation inside the same ad set sends it back into the learning phase.