FLStudio v20.0.3 [build 532] 64Bit on an updated Windows 10 PC.
As mentioned, the keyboard is the "SL88 Grand", and I tested the keyboard using Keyscape (as that is what I need the pedal for).
I've tried ...
note I played (C4), I hear no sound until I release the key.
BTW: Ableton Live doesn't have this problem straight out of the box, no config needed. Studio One on the other hand behaves exactly like FLStudio. ...