JoachimT
> I never had to copy ADMX/ADML from C:\Windows\PolicyDefinitions to our integrated
Because you never did, doesn´t mean you never needed.
There ist NO AUTOMATISM referencing to a Central Store. Thsi store is completly under the admins control. Whatever is inside or needs an update is a manuel deployment job by the Admin.
Depending on which 3rd Party software you use and depending whre this software stores it´s ADMx/ADMl you need o collect it manually and deploy it to the central store. because of your name, I think, german will work
https://www.gruppenrichtlinien.de/artikel/central-store-fuer-administrative-vorlagen
Simple rule: Always use the newest templates. No matter if it comes from server oder client OS.