No, this is not possible, at least not with DVB-C. Only a single tuner is available for DVB--C.
Since I don't have SAT, I know how it is there.
We have therefore taken out a Zattoo subscription. This works wonderfully in the meantime.
The switching between the Zattoo app and DVB-C has also been taken care of in the meantime. I hope it stays that way.
See also my rating.