Hi DesertRatR,
Welcome to Apple Support Communities. I understand you have a set of AirPods Pro that is not being full charged in the case while it's fully charged through a Qi-certified charging mat. I can help point you in the right direction.
If you're using an iOS device to pair your AirPods Pro, I recommend making sure that the device is updated to the latest iOS version. This helps ensure the firmware update on your AirPods Pro is updated. Here's a helpful article on how to update the iOS software: Update your iPhone, iPad, or iPod touch
In addition, you can also reset the AirPods to see if that helps resolve the behavior you're experiencing. Here's how: Reset your AirPods
Kind regards.