Windows 11 Channel output

I have been trying to set up my FLX4 to my monitor speakers, which are connected through the deck, and my headphones connected through the headphone port on the deck. I have been through every troubleshooting I know and cannot figure this out. The speakers will play when I use anything but Rekordbox on my computer. When I change the audio in RekordBox to DDJ FLX4 WASAPI, I am not able to load tracks and have no control over my controller. The only other audio option Rekordbox gives me is my RealTek computer speakers, where I can load tracks and mix through my computer's speakers. In the input output audio settings, no matter if I am set on external or internal output, I am not able to change any of the output channels (my only option is "-"). I can't find any help on this on YouTube or any other resource. Looking for any help or advice at all. Thank you!