@Bonus12 Thanks for posting in our Q&A.
For hybrid Azure AD joined devices, we can only specific the prefix for the device name and other 15 characters are randomly generated. There is no method to specific the device name as "xx-%SERIAL%".
https://learn.microsoft.com/en-us/mem/intune/configuration/domain-join-configure#create-the-profile
Hope it will clarify something.
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