It is possible to have a phase reversal somewhere that could extinguish the centre tone (the same in left and right) and leave only the signal that is different audible. Also the enhancer can have a similar effect. But it should only be a problem if the signal gets summed to mono somewhere after that.
So, if you have it, turn the enhancer block off. Check the chain for phase issues. Actually, turn every effect off except amp and mono cab, single IR. Turn them on one by one until the direct signal disappears. Check the standby settings on all of them (mute, through, etc.) and be aware of parallel effects in particular.
If that doesn't show anything, make a backup of the system file and an example preset and upload them here so someone can take a look. Specify the version AxeFx you have.
On my TV there is a stereo width function for surround sound which is similar to an enhancer. I only have stereo speakers on my TV. We were watching some singing competition and I was complaining the entire time that the sound was mixed wrong. The singers were hardly audible. Ruined the show for me. Couldn't understand that the sound was so bad and nobody did anything about it. Then I went to the sound on my TV and there was the surround enhancement on. Turned it off and there was the singers voice! The stereo function splits the stereo sound and sends the centre to the centre speaker in a surround sound system and reverses the difference in the rest. If you don't have a centre speaker that sound is gone.
Another story: a long time ago I was in a band, we'd bought a recorder and a mixing desk, we were mixing our CD. The other guitarist found a neat trick: he routed his guitar through one strip on the desk, then took the output and fed that into another strip and panned those wide, probably the recorder was in between too. Sounded thick. I said "Sounds great!" And then, being the callous bugger I am, pressed the mono button on the desk. Suddenly it turned all thin and nasal. The second track had delayed the signal just a tad and caused phasing problems.
In principle the headphone output gets the same signal as output1. Do the speakers on output1 behave similarly? Do you have a splitter cable from two mono jacks to one stereo female jack? You can use these in the normal outputs and plug in the focals and check if they're the same. 32ohms is not very high impedance so those outputs should be able to get enough volume to hear stuff. Generally the higher the ohmage the lower the volume with the same output signal. My DT770s are 250ohms, there's also a 600ohms version. Also generally headphones get more detailed with higher impedance. Do you have any other pair of headphones, ear buds, anything? Try those in the headphone output. Maybe the Focals are wired out of phase.
