I threw my face at hard mode for another hour this afternoon, experimenting, testing… I think I’ve found a passable if somewhat less than ideal workaround.
When I see a double charge coming, and I’m in the thick of enemies, I’ve started simply using the double-tap A evade to just clear out rather than risk a possible buggy double-counter. I’ve notice that the double-counter seems to have more issues in a crowd, where the enemies may be clipping into eachother.
If I evade out into open space, and they double charge me where I can stand still and only worry about those two enemies, it seems to have a higher success rate.
Like I said, it’s less than ideal having to exit the fray constantly as opposed to continuing a fluid attack string, but it does seem like the safer, and ultimately less frustrating alternative.