Hi,
This setup you describe seems the correct way to do it (copy the muxes).
Did you "map channels" for both devices?
Did both devices finish there initial scan (Muxes awaiting initial scan 0?
Also check if you can watch tv from different devices at the same time ( since it might also have to do with the recording-scheduling, and not with the muxes or devices.).
The systemlog ( down in the screen) shows what adapters are used when watching tv.
Alex.