So I am in progress of setting up my homelab and though I'd use some space for Veeam on my QNAP unit that I use for backup of laptops and PCs at home, and thought that SMB would be better to use instead of iSCSI. However, I'm running in to some issues when trying to configure a NAS target, and I'm not sure why.
I can browse to the share with Windows Explorer and authenticate properly, and if I map it to a drive I can see the correct amount of free space in explorer. There's a few things I've tried already:
1) Setting EnableInsecureGuestLogons to $true in SmbClientConfiguration (Powershell)
2) Changing EnableSecuritySignature to both $false and $true in SmbClientConfiguratio (Powershell)
3) Setting the NetUseShareAccess registry value to "1" in the registry
I have tried some different settings on my QNAP, this is how the SMB Server is configured

And these are the setting of the shared folder:

And share permissions:

I'm running Veeam B&R Update 4 on Windows Server 2019, and my QNAP is a TS-231P running 4.3.6.0805.
Any pointers in the right direction would be greatly appreciated.
/Andreas