DJM-S9 channel 1 glitch

When I raise and lower the volume up and down on the channel 1 fader my Serato DJ Pro starts to glitch. It starts controlling the channel 2 switching it back and forth from internal to relative. I've had my mixer since 2017 no issues. I haven't used it in 3 months because of no gigs due to Covid 19. Has anyone else dealt with this? Any solutions? Serato DJ pro is updated to the most recent version. I've restarted my laptop. And turned the mixer off for a while. Still the same thing.