Yeah, but are you still using the Edel?
Even if you're hitting the gate, are you hitting it really low on the face?
Look at some of the putting videos at:
30-Day Practice Plan - Golf Evolution
Yes, I'v been down near a 3 handicap, and now much higher. I think my swing is in a better spot than it was then. Just not scoring well. I had a 9 hole round where I had 6 pars, and 3 double bogies. I am trying to get it back down.
Also, if you were working on your swing, it could cause you could struggle on the course. Swing changes take time, and it can disrupt consistency enough to shoot higher scores.
Finally, did you ever keep stats of what is causing you to shoot higher? Hitting more shots OB, into hazards? Missing more putts? Messed up short game. Just thinking, if it is a short game or putting issue that you could get that looked at that. That sort of stuff is low hanging fruit.