K8600, stringing

Hello, I have a Vertex nano K8600.
I have stringing problems concerning my impressions. So I try to fix this using retraction distance, speed of retraction, travel speed, temperature, Z hop but I cannot solve the problem …

For now, the best result had obtained with :
travel speed : 300 mm/s
T : 185 °C
distance retraction : 12 mm
speed retraction : 200 mm/s
Z hop : 0 mm

What do you think about these values ? Do you have any ideas/ suggestions to solve the problem ?