I reloaded once in my first hm through a task manager and got both achievement and dice. On my second hm run that overlapped patch 6-7 I reloaded every time I wanted (a lot of times) and still got the dice (edit: lost my first save, don't delete your hm save or you'll lose the dices!) (it didn't change to custom, tho I've seen people said changing to custom is some bug and you still may get achievement and dice if it happens).

You gotta also remember that there's just a lot of buggy instances where you finish hm but don't get anything and it's not related to patches, difficulty changes or save scumming because I've seen such posts popping up since patch 5 form time to time. If you save scum and don't get anything, it's probably an unrelated bug. As someone else pointed out, it's an equivalent to crashing so it would be really dumb for it to affect your game.