I have 2 Devices Chromecast 4.0 (4k version). After last update to android 12 there is problem with app Play now ver. 1.14.2. . Video freezes the picture every few seconds. on another devices with android tv 9.0 and the same play now version this problem does not occur. so the fault in Google tv on Chromecast is on your side (your update messed up something).
I'm really sorry that your Chromecast with Google TV is having issues playing your app. I'd be happy to help where I can, so let me just ask you some questions:
There have been a few apps that need to be updated by the developer to function properly with Android 12. It may be beneficial to reach out to their support team to see if they have any updates planned for their app.
I look forward to your response, and if you have any other questions or concerns for me, please let me know!