I have had issues recently with datasmith direct link for vectorowrks. I checked with vectorworks support team and it seems like the issue is not from vectorworks itself.
When I have the direct link on, it does not show it as available in twinmotion and I get "no source available".
I have tried changing the settings but nothing works. Could this potentially be a bug?!
I had this problem for a long time and it frustrated me to no end. There seemed to be no solutions online anywhere.
I finally found out that the Datasmith link uses some kind of networking to work, so I tried turning off my firewall and it worked instantly. I tried allowing all Twinmotion and Vectorworks related apps through the firewall and that did not work however. I had to completely turn off my firewall for it to work.
Hope this helps!
-J