Hi,
Could you please to try setting up the Octane Daemon again, making the same setting for each render node?
In any case consider that just like in a multi-GPU setup, in network render, the amount of RAM available to OctaneRender is not the total amount of VRAM from your GPUs, but it is the amount of VRAM from your smallest GPU.
Let me hear from you.
Regards
Paride