Sorry about that. I don't have many issues with inputting mb. Lately I've been having a slight issue getting mb to activate when trying to input mb hook charge, but I think I'm just used to the old timing of the slower hook charge. All I can say is hit training mode a bit more to really get it down.
I have - I can get it to work more often in practice mode, but it's still an issue. I've tried hitting MB before, during, & after the input; I've tried tapping it lightly, I've tried smashing it as hard as I can, I've tried holding it down, I've tried tapping it repeatedly. It never seems to want to come out except at random occurrences.... And yes, I'm pretty good at watching my meter consumption so that's not it either. I've even swapped the controller's settings to no avail!
I hate not being able to get the MB to always work when I want it to - it affects my game. For example, if I want to do a MB hook charge upon wake-up, I won't always get the 2 hits of armor to vastly improve the attack & end up getting knocked down mid-stride. I have a similar issue with my main, Lex Luthor - I can't seem to MB his gravity pull which is nigh on essential for extending his combos.