Any chance my problem is with the SAT->IP's positions ?
I just assumed I should turn them all on, but looking at the doc apparently those are meant to select the dish, so I probably shouldn't. Is there a way to know which one(s) I should be using on each tuner for a digibit twin ?
This might explain why re-scans find more channels, if it's randomly using invalid positions. Not sure why the twin reports 4 positions since it's only got two inputs.
EDIT: It looks like the inputs are not shared, I tried all of them one by one and as far as I can tell each input is linked to one of the two tuners, and the dish position is always AA. I'll try a scan with just one of them on AA only, see if that makes a difference.
EDIT 2: Using just position 1 (AA) of one of the tuner I got a few more channels, but still not Freeview. Most of the channels found aren't actually playable, it's finding things like "Discovery" unencrypted on 12382.5H which isn't right. Some like Sky News are playable fine, so the hardware definitely works. Could the dish be misaligned or the cable damaged and get only some muxes ?