Quadcopter yaw issue

I have built a quadcopter(X configiguration), and as a control unit I chose Cube black controller.
I configured the vehicle through Mission Planner, and flashed the latest arducopter firmware to controller.
Quadcopter can hold stable yaw angle, but the problem is that motors 1 and 2 (see airframe reference) have much higher rpm, than motors 3 and 4. Motors 1 and 2 have about 1700 PWM values, motors 3 and 4 have about 1300 PWM values, thus motors 1 and 2 are much hotter on the end of flight.
It is like drone has a tendency turning CCW, so motors 1 and 2 need to work harder to stabilize yaw angle.
When i move yaw stick to the left, drone is reacting well, butt sluggish when the yaw stick is moved to the right. I have tried flying with different controllers(cube orange), and different quadcopter configurations, but result was the same. I’m using T-motor MN2214 KV 920 BLDC (Graupner C-prop 9x4 inch).
What might be the problem? Thanks in advance!

This is usually a mechanical problem the frame/arms/motor mounts resulting in the props not being level. Arms/motor mounts twisted, frame distortion, etc. It’s regularly seen on multirotors with round arms.