Ad no longer ready/available after loading new scene. (Unity Ads)

Hi there. I use Unity Ads. I have two scenes: - Menu scene - Game scene

In the Menu scene, my ad manager object loads an ad until it's ready. However, if I load the Game scene after an ad is ready in the Menu scene, no ad is ready in the Game scene anymore.

In other words: The ad-ready progress resets when switching scenes.

Is that supposed to happen? How would I fix it?