None of the links work?

None of the links work?

EDIT
I think what you might have missed is the link switch – this is common on two channel inputs – so one mic goes to both channels, in the wrong position, one channel won’t work.
select input 1 to ch 1 (left switch) then each input to 0dB to start, and mic, not line. You can select 48V phantom power if you need it. P