Orbi uses 80 MHz channels for both client connect and backhaul.
NETGEAR confirmed that the same 5 GHz channel is used for client connect on both router and satellite. They said this makes it easier for some clients to smoothly roam.
After thinking about this, however, there is also a more obvious explanation. Since backhaul uses all four 5 GHz high-band channels and DFS channels are not supported, there are no other channels available to use!
NETGEAR confirmed that the same 5 GHz channel is used for client connect on both router and satellite. They said this makes it easier for some clients to smoothly roam.
After thinking about this, however, there is also a more obvious explanation. Since backhaul uses all four 5 GHz high-band channels and DFS channels are not supported, there are no other channels available to use!