UR22C one channel louder than the other

Hello, I purchased UR22C and ran into a problem, when connecting Audio-Technica ATH-AD500X headphones, the sound in the left ear is a little quieter than in the right (especially in the middle and upper middle in the frequency spectrum, in other words in the vocal area)
It is also possible that the following is connected with this - when the headphone volume knob is lowered to almost zero, the sound in the left ear disappears and remains only in the right ear until the volume is completely turned to zero. All actions are performed with the MIX knob fully turned to the far right (DAW) position. Firmware and driver new. I changed the adapter from 3.5 to 6.3. I tried to supply power from the adapter, not from the computer, all to no avail.
I also updated the bios and reinstalled the yamaha driver several times. I saw several similar threads on the forum like mine, but they did not have a solution. Is there a solution now?

Have you tried another headphone to check the problem?

Of course yes

The mix knob should be in the centre position (detented) when listening back to a recording etc. I always have the mono button depressed as well so sound comes out both sides.