What is your DAW? In Logic Pro X, there is a setting that can be instantly managed to set its panning. Negative values for left, positive values for right. Maybe if you have a direction mixer, that might help?
I use BandLab,and it does the direction mixer automatically set the pan or is it manual?
By default it is set to 0, it looks like the DAW is missing the knob to panning. Your alternative is to move to automation and set the panning from there instead.
Also, if it’s a mono audio, you’re going to face issue if the output is mono. If you can put it on stereo mode, then proceed with that.
I know that but I’m just wondering how should I correctly pan my instruments to make them sound good