Hello,
Have you changed your group policy which specifies your license server? After you migrate your license server to a new one, you can edit your GPO to achieve license CAL from the new server.
You can follow the step:
a. Create a GPO and link to the desired containers
b. Navigate to Computer Configuration - Policies - Administrative Templates - Windows Components - Remote Desktop Services - Remote Desktop Session Host - Licensing
c. Double click Use the specified Remote Desktop license servers, set to Enabled and enter the names of the license servers then click OK
d. Double click Set the Remote Desktop licensing mode. Click Enabled and set the licensing mode then click OK
e. Close the GPO
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