Hello,
firstly, please note that us at Corona, we work primarily during the work-weeks, therefore user support is limited during the weekends.
Secondly, we are aware of this issue with Rebus farm, and for now we recommend not using "shared shaders" inside your materials, that means, to not have one node output connected to multiple other node inputs (= copy the shared nodes and have 1:1 assign ratio). I am attaching an image with a very simple example.
I know this can be very tedious for a large amount of materials, but it is the only workaround at this point.
Thank you,
Jan