UR22C - Audio output issue

Hello everyone!
Facing some weird behavior with audio output on my UR22C.
The connection chain is as follow:
1- 2 Synths (behringer deepmind 6 / synthstrom deluge) → UR22C → DAW
2- Each synth is connected to UR22C by jack-jack cable (2 mono jack → 1 stereo jack (Y-type) cordial).
3- I have two stereo jacks from each synth connected to UR22C Input 1 and 2
4- Monitoring audio output through Logitech pro x jack 3.5 → adapter to jack 6.3 → Phones input on UR22C

What’s happenning:
If knob of UR22C is turned on INPUT position → all instruments are audible in both channels
If knob turned on DAW position → all sound from both synths are: only in right channel of my headset with significantly dropped volume.
What’s strangest part in this story: if I turn the PHONES volume to max → left channel is appeared with overal very poor sound quality (like distant, quiet).

Additionally, the UR22C when monitoring only INPUT does not reflect the PAN of the synths (meaning that when I’m panning sound only to RIGHT channel → sound disappear, when in the LEFT channel → I hear sound in both channels (??)

I went through drivers update, VST check, FL Studio check → all seem to be in its place. Synths are fine: tested pan on the speaker: works fine: L to R pan goes OK.

Is anyone faced same issues? Any thoughts on what can cause such strange behavior?

Thanks in advance for Your advices and feedback!

PS: back in the days I used only 1 synth and hook up the sound from headphones output to UR22C and basically all was right. Except for now, when 2nd synth appeared I figured out that 2 LINE INPUT cannot sound at all without HI-Z button.

Inputs on the UR22C are mono and you are plugging a stereo jack into each input, is that right?