Recent versions of Windows 10, and Windows 11, have a default 10-day Limit to go back to previous version of Windows after an upgrade. The setting can be confirmed by running a simple dism command:
Dism.exe /Online /Get-OSUninstallWindow
Extend the 10-Day Limit
Changing the setting can also be done with dism, the command line switch for that is /Set-OSUninstallWindow and then you provide a value via the /Value switch. Here is an example that changes the rollback time to 20 days:
Dism.exe /Online /Set-OSUninstallWindow /Value:20
Adding this to your upgrade Task Sequence
Here is an example task sequence configured to allow rollback for 20 days, the command added after the upgrade was completed, meaning in the Post-Processing group.