You are mistaken.
Apple iOS devices and OS upgrades do not install third party stuff.
Something has changed on Channel Master's end that clearly you may not be aware of.
Just as an experiment.
Try the new hard reset procedure for the 2018/2020 iPad Pro/IPad Air 4 models without a Home button.
1. Press and release the volume UP button.
2. Then immediately press and release the volume DOWN button.
3. Then, press and hold the Power button at the top.
You will see the Slide to Power off button, but keep on holding down the Power button until you see the Apple logo, then let it go.
Once you have performed all the steps, wait for a few seconds and your iPad Pro will boot up completely to the iPad Pro’s Lock screen.
If no joy, can you explain to us the procedures and settings you use to stream your iPad to your DVR?
Is it over your Home WiFi network?
Do you use an app to connect your iPad to the DVR?
We have no idea how you are trying to stream content from your iPad to your DVR.
In the Disney app under Accounts, is stream over WiFi option toggled ON/active?
What about the settings within the Prime Video app or any Pime Video app settings found in the iPadOS Settings app?
Are all your WiFi and streaming app settings setup correctly?