Engine Stall on start up - "Engine Fault: Workshop!"

Every since I got my Yeti 4x4 170 almost a year ago, it's on the rare occasion stalled immediately on startup and flashed up "Engine Fault: Workshop". Then if I turn off the ignition and restart the car it always starts up no problem.

I've since had the software rolled back to pre-emissions fix and had a remap applied, which I did wonder if it would make the problem disappear, but it's not been the case.

I'm not sure if there's any real pattern to it, doesn't seem to be temperature related. It might happen once every 2 months, might happen once every few weeks. Again it's not a regular issue, but I'm not sure if it's the early signs of something going, EGR etc.

Not had a chance to get it plugged in and have any fault codes pulled, which may well help diagnose the cause,

Anyone experienced the same?