Hi
In case a corrupt .admx exist, did you tried to get the latest Windows 10 ADMX and to upload the content to your SYSVOL\domain-name\Policies\PolicyDefinition's folder ? (\dc-name\SYSVOL\domain-name\Policies\PolicyDefinition)
The ADMX is here; https://www.microsoft.com/en-us/download/details.aspx?id=103667
If you have the Windows 11 ADMX some Windows 10 settings can be missing. It all depend on what are the most computer you have inside your AD, Windows 10 or Windows 11.
Windows 11 ADMX is here; https://www.microsoft.com/en-us/download/details.aspx?id=103507<
I suggest to take the ADMX that fit more your case here, as the newer ADMX miss some settings for Windows 10 and vice-versa.
If you dont want to change the policy from your 2019 DC and do an isolated test, you can install the RSAT tool inside your local computer, the ADMX used to create the GPO will be the one that is from the RSAT toolkit. The only thing that would happen is if you open the GPO from the 2019, the missing option will be displayed as registry settings.