So you've got the source info, the helper deployed, and the worker connecting to it, It remains only the helper connecting to the source. The relevant logs in this case are the helper's ones. However you may not need to look for them. The required connectivity in this case is: a machine from the virtual network (where the destination VM is created) needs to access the source machine at port 22. Also the source needs password authentication enabled. You need to check virtual network routing, firewalls, and source machine's sshd settings.
I suggest you get a neighbour machine from the same destination network and try to ssh to the source machine. Once you succeed, proceed with the conversion.
HTH
Plamen