Photographers' Formulary said I could "go ahead and use the glycin" which has turned cocoa colored (outdated, although they don't put expiration dates on the container) in the Ansco paper developer which I mix according to Anchell's Darkroom Cookbook. I have mixed it and used it on Forte VC fiber paper (and Ilford RC for contact sheets). Prints from a Bergger neg look good, but prints from an HP5+ neg have blasted highlights, regardless of burning (detail is in neg). Is the age of the glycin a factor?
Assuming your HP5+ neg is ok and does not have too much density in the highlights then I would say yes, the Glycin is the culprit.
I've been using Wynn White's WW-1 glycin based developer with Forte paper and a few others. I have in general noticed that the Forte papers do not go as low in contrast as the Zone VI Brilliant and the Oriental Warmtone, which may explain your blocked highlights. Of all of the papers I have tried with this developer, the Oriental warmtone has the nicest, warmest tone that just turns absolutely beautiful with a brief selenium toning. It will also give a reasonably low contrast print (i.e. print a high contrast negative properly), unlike the forte. FWIW, Wynn's website mentions out-of-date glycin, and says that it gives darker stained highlights, not blasted-out highlights. Check out www.wynnwhitephoto.com