Ad content rating for different types of apps

Recently, Google Play complained about my app's ads:

Issue found: Ad Content We found an issue with the ad content in your app:

The ad content in your app is not consistent with the app's content rating. Issue details

We found an issue in the following area(s):

Version code 126

So to fix this, I changed the ad content rating in Admob:

So that's fine. I submitted another version (with no changes, just the version) after changing the rating and they accepted it.

When changing the rating to General Audiences, it mentioned that I'd get fewer types of ads and less money.

The problem is that this rating is global to all my apps. For this app in particular, it's fine, because it's an educational app for kids, but I have other apps related to finance and investments for which I'd like to display more mature ads, especially if that means more earnings.

How can have different ratings depending on the app?

The ad content rating is also available for each individual app, so this has to be changed instead of the global one: