Line mark on the surface of product

We have tried to get rid of this line mark on the surface of product but we couldn't we have tried with injection speed but no change.
what do you think?
material: PP
thickness: 4,5 mm
cold runner 2 gates

thanks in advance

could you please insert a picture of whole part and mark a injection gates location?

Thank you for your reply

Thanks for pict. It is not very clear from images, what is going on. It can be also wall thickness issue or pressure marks. Do you have it also on short shots?

thank you for your reply
there is no sink mark on the product, it is just like a white line around the product in the middle
I thought that it is from the changing of flow direction inside the product( pic 2) so I am thinking to make it done more smoothly.
that do you think?

thanks and best regards

Could it be from color concentrate?
Maybe try 100% regrind to see if it changes.

Looks flow or temperature related
Or maybe the part is stretching during mold opening