I really double check filament calibration, made all the step, print flat layers perfectly, aswell as PA lines test, definitly not related to flow calibration, but maybe related to flow.
With Bambulab PLA : setting infill/wall overlap to zero give a very good result.
With low cost Geeetech PLA : a lot better but not perfect
Note for myself : never buy again low cost Geeetech’s PLA :), there is one filament (silver) I cant print (it clog at middle of each print) and others not look good (weird color) or seems to print with more issues than other filaments, at least it is cheap,11€/Kg but maybe I will throw away half of the seven spools I bought (joke they will go on my other printer)… finaly only the white seems to give good results.
Results with PLA Bambulab :
Perfectly lined up !
EDIT: picture is 0.2 layer height