We've encountered an issue where meta will override our campaign settings with their automatic adjustments.
This can hurt the performance of your campaign, and will prevent your ads from being shown to the correct audience.
1. To disable these adjustments, just go to "Account Overview" inside meta ads manager or click on the following link https://adsmanager.facebook.com/adsmanager/manage/accounts
2. Click on the button "set up automatic adjustments" or "edit adjustments"
3. When this menu pops up, just make sure to turn off automatic adjustments and uncheck / disable each section if needed
Finally, just keep in mind that these changes will only be applied for your next campaign, so if you previously launched a campaign with audience network placements, you may need to delete it / turn it off and launch a new one.