I am trying to setup hybrid access to a new FileShare in Azure. We are using On Prem AD with sync to AAD. We are also running 2 DCs on prem and 2 DCs in the Hub VNET in Azure There is a conditional forwarder on the 2 On Prem DCs for core.windows.net to go to the 2 Azure DCs. The 2 Azure DCs have conditional forwarders for core.windows.net to go to 168.63.129.16.
I have gone through all the setup steps within MS documentation and have a connection to the share when using the address sharename.file.core.windows.net. This is also working across the privatelink, so I can see when DNS Resolving, that it is actually a CNAME to sharename.privatelink.file.core.windows.net which in turn is correctly getting the internal IP of the Azure FileShare.
The issue arises when trying to use a CNAME that is a bit more business/user friendly, such as data.companydomain to sharename.file.core.windows.net. Again, I can see that this correctly resolves to the IP address, but if I try and access the files either by mounting the drive or UNC to it, I get a Username\Password prompt that doesnt work with an allowed domain user credentials. I seem to get an error code of 0x80004005 even when using a global admins login.
Is this possible to setup? And if so, can I have some pointers please?