Zgemma H7S client mode

[digitl]

I've a couple of Zgemma H7S boxes, both with twin satellite tuners, a single terrestrial tuner, a 1TB SSD for storage and are connected to Gigabit Ethernet. However, each has only one satellite feed and one terrestrial feed. Additional feeds were planned but I've decided to go down the client route with a Vu+ Duo 4K SE as the server which is also on the Gigabit LAN. I'm hoping, also, to save recordings set on them to their internal storage, watch channels using the Vu+'s tuners and watch recordings saved on the Vu+'s SSD.

I'm working with just one of the Zgemmas to get things sorted but have hit a bit of a brick wall in that if I try to schedule two concurrent recordings then I see a conflict notice. Should I assume that it isn't seeing the Vu+'s two Unicable feeds? If so, what do I need to do to fix it please?

Or am I attempting the impossible?