Inconsistent back slash?

Not sure if anyone experiences this, but I feel like about 15% of intended combos into backslash [ (R2) -> (Down + R2) ends up me going backwards. I get a bit frustrated since it leaves possible damage off the table, even worse if I knew it could've finished the opponent off. Could it be a controller (playing on PS4), latency (US) or am I just shitty? Also I tend to do it more often in certain MS like Pale Rider Heavy Ground than GM Command. Been practicing trying to fix it, but still get inconsistent results. Any tips on timing would be helpful.

Edit: Thanks Reddit! It has been resolved, it was due to button mapping. Gonna have to readjust how to use controls after being used to my layout for the past 6 months.