Does anyone have experience with Briot edgers? I'm having axis issues.

I've been edging for a dispensing lab for about a month now and they have a Briot Perception 2 edger. I've noticed a consistent trend of jobs coming out 3-5º off-axis. Of course this is mainly an issue on line bifocal and high-cylinder jobs. The machine uses a photographic lens tracing method. In response to this issue, Briot suggested that it was user error in the tracing stage. I don't believe this is correct because the lenses are turning the same way, like this / /. I check the trace against the frame each time to verify that the axis is correct and make any adjustments, but when the trace axis is off, it looks like this / \ or this \ /, because it's creating a mirror image of the single traced OS lens to form the OU pattern. It seems to me that, given precise blocking, it could only be that 1) The lens is slipping (I am using the strongest pads and the AR stickers and running the machine slowly, so I don't think it's this), or 2) The machine is cutting off-axis. Any advice or insight would be greatly appreciated. Thank you!

Try this
Calibration the edger.

you can import job pattern via usb (so exclude tracer problem)

You can block a sample lens manually or with another blocker if you have it (so exclude a blocker arm problem)

You can try another lens sticker or ar brand and let's see..

You can try to clean roughing and finishing disks