Cannot get the NIM despite 24 SCR channels

[Alexwilmac]

Lately I get the error "Cannot get the NIM" despite I've got a FBC tuner correctly configured with 7 SCR channels for my LNB and the LNB has got 24 SCR channels.
But, if there's just a box streaming by Fallback tuner configuration, I get this incredible error.
It's not necessary to tell that every other activity involving multiple tuner needs (multiple watching/recordin/straeaming/PiP) perfectly works.
I also tried, just to do something weird and not logical, to change the preferred tuner in my image (OBH 5.0.008).