Yes that is it exactly. It slips then catches. Sometimes with a little bump
as it catches. Fluid is spot on. Measured when warm with the engine running.
I am hoping it works itself out and gets better but if not I will try
putting conventional fluid back in see if it makes any difference. Merv

Are you sure you have the fluid level right? It doesn't take being off much
either way to make it act funky. By "slipping", do you mean that you give it
gas and the engine revs up readily but the tranny is sluggish to catch up?