Newbie, new DM 920 UHD, with double DVB-T2 DVB-C tuner.
Bought a extra double tuner DVB-T2 DVB-C, to get 4 active DVB-C tuners.

Now when start one recording, swap channels stops working, only some channels works.
Without that extra tunercard everything works as long as I only make one recording.

Trouble I have no real pdf manual, only quick start guide.
And I'm not familiar with DreamBox OS, need manual for that too.

Before DreamBox, I was using Miraclebox premium twin HD, with OpenATV nightly (but broken trash now)