Is that a encoder gimbal? with what connection have the encoders been connected?
I fail to understand "and my yaw board have a capacitator to cover up voltage lacking symptoms"
But over all it looks like you need to rethink the i2C cable routing, route it separately from other cables and use as short cables as possible. Use ferrite rings if needed on motor and I2C wire and if nothing else helps shied I2C cables, but for that you need good understanding of I2C related stuff, and an oscilloscope.