Hi Mlehnn,
We appreciate you reaching out to us. We understand that you are experiencing issues using screen mirroring from your iPad to your Apple TV.
We’d like to gather additional details that may help us be in a better position to assist you.
Are you not able to screen mirror or AirPlay from any app at all?
We ask because some video apps might not support AirPlay.
Do you have a different iOS or iPadOS device that we can test with? If yes, are you experiencing a similar issue with your other device?
In the meantime, let’s check for a software update and make sure that you are running the latest version of iPadOS.
While it isn't inherently assured that an update will resolve the issue, updating to the latest software version for your device can help isolate potential software issues.
Kindly secure a backup and update.
How to back up your iPhone, iPad, and iPod touch
Update your iPhone, iPad, or iPod touch
Let's also make sure that your Apple ID is up to date.
Update your Apple TV
Take care!