AXR4T Loopback without using AXR4 2TR driver

I seemed to be experiencing some issues with loopback implementation which was working prior to updating to AXR4T latest drivers. This may just be a coincidence but wonder if someone who uses old school manual loopback can give me some pointers re my setup.

On the AXR4T I use the digital b port for AES connections. I use the AES 7/8 for loopback connecting its physical XLRs Input and Output together.

If I set the Output on the Steinberg Thunderbolt in the Mac Audio Midi Setup panel to AES 7/8
ie anything playing on the Mac routes its default output to AES 7/8 Out it should route that output to the AES 7/8 input allowing to record.

In the AX4 dspmix app I can see on the meters that the signals appear to be present and I can hear them in the headphones when switched to the AES7/8, but I seem not to be able to record the signal from the AES7/8 input in Wavelab.

Is there a step Ive missed somewhere?

Im certain I had this working before but doubt has crept in and Im trying to rule out the possibility of the Thunderbolt driver update introducing a new issue, especially as we still have the unresolved 32bit integer issue.

Any help appreciated