Tvheadend

I have noticed lately when recording I sometimes get adapter is busy message even though there is another adapter available.

I have one satellite and one freeview tuner.

freeview card has priority. Identical channels are merged into one. sat+freeview.

Say recording channel 5 which is a merged channel, I can then not watch any of the other channels that have been merged even though the satellite card is free.

The satellite channels that are on their own and not on freeview continue to work fine.

So on the merged channels the problem is that tvh does not fall back to the lower priority card if the higher card is busy for merged channels. Is it a setting I may have missed?

Cheers.