Hi @Elroy ,
Could we know the upgrade is actually works? Do these client version change windows 10 1909 to windows 10 20H2?
If so, we could check Smsts.log to see if task sequence activities is ended on the side of client.
On the side of server, please navigate to monitor, deployments, the task sequence we deployed, check the status is successful.
If the task sequence is normal, we could run the policy on the side of client or restart the client to check if the problem is solved.
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