I am beggining to regret my purchase

Your air flow is maintaining during the cut? If it drops below 85 during the cut you at risk of extinguishing the arc. Also it is really hard on consumables.

I ask about the manual because the current doesn’t show the use of a single row swirl ring anymore your edition in your picture does.

The current manual only shows the double row for all of the charts

Your main issue does seem to be getting a proper Arc voltage measurement. So let’s solve that first.