This is most likely due to different additives mixed in the PLA. You have similar effects between matte and glossy PLA. Your profiles show, that you also have two different PLA mixtures, black is their PLA+ while the violet is their silk version.
Unfortunately, eSUN does not provide the MSDS for the PLA eSilk, but here is the one for the PLA+: https://www.esun3d.com/uploads/PLA＋-MSDS.pdf
As you see, it has between 4 and 8 % different additives, which change the flow characteristics as well.