New to Inverters

I have been welding and fabricating for over 45 years, professionally for more than 30. I have been certified under numerous AWS and ASME procedures in the nuclear industry. However I am new to inverters, having just purchased an Everlast Powertig 255 EXT. I am having trouble with arch stability at low settings on aluminum, specifically beverage cans. I can run a nice bead welding two together with my old Miller 250 HF set on 25 amps. That’s using a WP 26 torch that is stiff as a board, a 3/32 tungsten and 3/32 or 1/16 filler. I will post in the appropriate section to find out if the problem is me or the 255 EXT.

Current welding equipment:
Miller 250 AC/DC HF TIG/Stick, Miller Dialarc 250, Millermatic 200, Cutmaster 52 plasma, Welding Rig with Lincoln 225, Quincy air compressor and Victor cutting equipment.