Use something other than LK Run to go into Pummel Horse, or use the old timing.
I'm going to explain this
one last time, in incredibly easy to understand terms.
Hitstop is when the game freezes for just a moment to emphasize the impact of hits. Soul Calibur does not have hitstop, and as a result sword swipes are incredibly smooth-looking when they cut through you. Blazblue has too much hitstop, and as a result combos look like slideshows.
During hitstop, the game is considered paused. Inputs are buffered until after the hitstop is completed, but the game considers them to all have been input simultaneously. If I do s.HP xx Lock 'n Load, and I input LnL during the s.HP hitstop, LnL will come out
immediately upon hitstop ending. If I do s.HP xx LnL xx Dynamo, inputting LnL
and Dynamo during hitstop during a moment of flustered mashing, I will immediately and ONLY get Dynamo.
Cerebella's Run is basically like a rekka. It's a special move that cancels into other special moves. There's a catch, though! The Run has to
start before you can cancel it into anything. So, before, inputting Kanchou or Battle Butt during hitstop would just result in getting the run of that particular button. The run hasn't started before you tried to cancel it into a move!
The new fix lets you input a follow-up command during hitstop, provided you're holding the button down when hitstop ends.
If that follow-up command uses the same button that you used to initiate the run, the game doesn't know you let go of the button at all. This is because the game was effectively paused the whole time. It would be like if you raised your right hand, then I closed my eyes, you lower your right hand and then raise both hands, and then I open my eyes again. To me, I have no fucking clue you ever put your right hand down! That's the game right now.
The old timing still works. Nothing CHANGED about that. You can still do your instant Pummel Horses with LK Run if you use the old timing that required you to do it during the recovery frames of s.HP instead of during the active frames. You can even do the old 1-frame-link Kanchou! You can do Kanchou after an MK Run using the old timing! However, if you like, you can also use the new timing, but only if the follow-up command doesn't use the same button you used to initiate the run command.
The game thinks you're inputting Run Stop. That's because the game thinks you're just holding down LK and then hitting LP, which is Run Stop. Wait a few frames; according to the people in this thread the timing is "no big deal." Alternatively, I bet using MK or HK Run would solve the problem altogether.