Bunchberry makes an interesting native groundcover (clean foliage, fresh white flower bracts in spring and fall berries), and as you may have experienced, it can be finicky. Maybe its time to read the directions on this coveted native:
-Plant in partial to full shade
-Needs moist, acid soil, rich in organic matter
-Mulch well (if planted under an evergreen like White Pine, the needles make a great mulch for it)
-Water frequently until established (as a Zone 2-6 plant, a very hot, dry summer will cause stress)
Give it a try and let us know if you have any tips!