Added this note after I posted. Sorry for any inconvenience: I had MIDI-OX enabled and it was somehow echoing back causing two notes for every input. It was either that or my Sparrow fader. Removed both and no more double notes.
I've never had this problem before, but every time I record MIDI notes, two notes back to back are getting record instead of just one for every note I play. See the screenshot below. What could I be doing wrong?
After removing MIDI-OX and Sparrow fader:
Hardware
HP Z4 G4 i9
64GB RAM
(1) m2 SSD Drive
(1) SSD Drive
Software
Windows 10 Professional
Studio One Pro 5.5.2
BBC Symphony Orchestra Pro