If i looked at my chart right your getting a weak spine reaction.
I know your shooting 60# w/ a 5575 arrow, but from what I've read on this board, most solo's like a stiffer arrow.
Just for grins try dropping your draw weight down to 50ish and see what happens, or try flinging one of your aluminums to see what it does.
I would suggest shooting a lighter weight head, but that might put you too close to 5gpp, I'm not sure.
I shoot my solo pat at 65# and it currently wants a stiffer arrow than my Beman 340's.
Are you shooting the stock slide, or have you gone w/ an aftermarket job?
I lost faith in my alpine glide slide & went back to my factory slide and then to a hicks. Not sure if it was an issue or not, but I ruled it out