As @brent113 suggested, based on your image it seems to be tied to areas where acceleration/deceleration is taking place and so may be linked to linear advance. Linear advance is essentially a flow compensation that is applied when the print head is accelerating/decelerating in an attempt to achieve more even extrusion across a range of speeds.
Below is a post I made on this but if you search “linear advance” or “k value” on the forums im sure there will be a wealth of information on how to calibrate this.