Hi Harvey,
I am Sumit here to assist you with this question.
20H2 and 21H2 share the same codebase so I do not think your program compatibility should be affected.
In any case, You need to remove the enablement package, that would bring you down to 21H1. Then remove the 21H1 enablement package again:
https://www.yourwindowsguide.com/2021/05/uninst...
Go to Settings>Update and Security>View Update History.
Click Uninstall Updates.
Select “Feature update to Windows 10 21H1 via enablement package” right-click it and choose to uninstall.
Restart the PC to remove the update.
Please note that Windows 10 20H2 support ends next month in May.
Hope that helps.
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