Flashforge creator pro 2 with PLA, standard quality preset, textured removable magnetic bed on the build plate.
The first lines are straight, but as it makes more parallel lines to build the layer, it starts to develop a scalloped pattern. This creates issues with smoothness when it fills back to join it from the other side later. I’ve leveled the build plate, although I suspect it’s not perfectly flat and maybe slightly higher in the middle. Is this my problem? It appears to have the pattern even away from the middle if that makes sense.
Glass bed mods (glass is always dead flat) or careful adjustments of screws and tramming of the bed, depending on your printer design. Or find a way to sample more points when leveling the bed to compensate for the unevenness. (I have a Snapmaker 2, which shipped with a firmware bug relating to levelling that wasn’t found for quite a long time. Those were the most common fixes and mitigations.)
Glass is not always flat speaking as someone who just swapped their stock glass bed due to warpage (>0.4mm). My new aluminum bed is now within 0.01mm from side to side.