Re: Starting to think Nodachi is the buggiest weapon
If it's not the gamepad, sounds like you have some latency issue that's making your game drop inputs. I'm on the PS5, and I've fought Lavaback with the Nodachi and I've not had this issue with my charge not registering.
Also a trick to charge faster, charge the weapon, place a spring board, walk into the spring board and then hit the monster with your double regular attack that will charge your meter 2/3 of the way, hit the monster one more time while still charging to get your meter like 98% charge, just wait a split second for it to fully charge and then let go of the charge to expend your heavy attack. I don't do regular charge attack anymore to build meter, I find it a bit slow so I will always use this spring board method, I find it to be more consistent than the celestial thread.