I ran into the same thing. I’ve always just worked around it, but I believe I did find the solution at one point (can’t find the link now).

But if I am remembering right, I believe you need to manually create a bridge between the two networks - by default it isolates the VMs from TtueNAS itself for security reasons.

Sorry I can’t link the exact fix right now, but hopefully this will and you on the right direction.