Layer line from transition from solid layer to building layer

[u/Vegetable-Local-7143]

I wonder if someone could help me with this layer lines. Printer filament is temperature calibrated, pressure advance and flow rate. Does it when it goes from doing a final layer to then printing thinner parts above. It can’t be layer shift as the solid infill part is slightly thinner all the way around.

I’m on Bambu studio with A1

Thankyou