I don’t have a Passagemaker, but have been sailing balanced lugs for years. The first thing I’d check is fore and aft balance. If you’ve got too much weight in the wrong spot you can induce lee helm which would keep you from going upwind. Typically it’s been sitting too far back for me. This can be fixed by moving forward or putting weight up front (passenger, drinking water, other supplies, ballast, etc.).
Another possibility is the sail shape. First, the draft (deepest part of the sail). You may need to tighten your outhaul if your sail is drafting too far forward. Second, twist. The leech (trailing edge) may be getting pulled too flat by twist and losing the ability to generate power. Reduce twist by tightening your downhaul.
Here’s a great discussion between a pair of PMD owners about tuning the rig.
Good luck,
Laszlo