I was having trouble calibrating my machine the other day (shenui 350 50w blue and white) and I thought that I would run a test of circles and ellipses to see how bad it was. I noticed a weird behavior in start/stop alignment. I then tested it in rdworks and had a different result.
I ran the same program in all 4 corners of the machine. I drew all the shapes inside their respective program. I used the same settings of 25mm/s cut and 20% power (~8mA). I cut on the same material.