Wait, 250%? That would make the problem even worse. Just use my file you know it is correct.
You can adjust the layer height while the machine is making the “priming loop but you should really just keep adjusting the z endstop screw. To thin means you need to slightly loosen the z end stop screw. You should be able to see the individual paths of the filament in ever single layer including the first.
If you did not adjust that driver it is running at 1.6V almost 3 times the recommended value you should stop immediately and turn it down before you ruin the extruder stepper. This means is it actually not extruding the right amount because it is going in and out of thermal shutdown.