Long straight lines are prone to curling. Your options are some sort of adhesion aid like a brim or mouse ears or slow your print down. You may find a combination works best.

Modern slicers also have settings for slowing your first layer as well as setting a number of subsequent slow layers that transition into your normal speed. I would start by increasing the number of slow layers to something like 10.

The number one enemy of any 3D printer is physics. In this case it’s the physics of rapidly laying long straight lines of molten plastic on to one another. As those layers cool they shrink and pull against the previous layers. If the previous layer has sufficient time to cool then that reduces the shrinkage and the forces applied to the previous layers.