hmm, dunno but…
considering your last picture it seems your “Yaw” value is fixed, since yaw is responsible for Up/Down(around Y-Axis) rotation and Pitch is for Left/Right (around Z-Axis), this is in 3D space.
So when you want to LookUp/Down you should update on Yaw, than Pitch. And when you want to turn you update on pitch, except you intentionally inverted those for a specific purpose. (sorry i saw that just yet).
but wait a moment