It seems that the Veeam support only works at 5am! so I'll ask for help here too whilst I wait for a response.
Restore testing failed when running restoring 6 VMs across multiple jobs. VDDK operation timed out: VDL_Close, all VMs stopped at the same time, but when I tied again one at a time, they restored fine so the data is ok.
In the proxy app event logs I also see many Event ID: 33, SideBySide errors. "C:\Program Files (x86)\Veeam\Backup Transport\x64\vddk_6_0\bin\disklibplugin.dll". Dependent Assembly Microsoft.VC90.CRT,processorArchitecture="amd64",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9. 0.30729.4148" could not be found. Please use sxstrace.exe for detailed diagnosis.
Restore Logs are uploaded into the case and they mention some c++ errors.