Hey @ItsMeRich sorry to hear that you encountering issues with the app on your Pixel 4 XL.
First try all of these steps to fix the app. You can also try to remove and add your Google account again on the device, that might fix the issue as well. Just have in mind that you better do a backup before, just in case.
If none of these are helping, try to contact Stadia support to get more help regarding your issue. Might also be a Pixel 4 XL problem, who knows. ![]()