When you say as a media player- do you mean listening to tracks in offline mode?

Yes. Offline mode, I assume, is using the software just for playing tracks via my laptop. Not using the hardware.

But it works ok when EQ is connected to it?

Also what platform are you on? OSX/macOS or Win?

Windows. I haven't connected it for a while. Software is up to date. And TBH, connecting the hardware is not possible now. But still, the issue shouldn't happen.

Just trying to figure out if it's a Windows audio issue, Serato issue, or what.

Might help seeing if there is an update for the machine's onboard audio chipset since that is what Serato is using during offline playback.

Yeah, My first though would be to check your sample rate for the built in soundcard.

Seems to be working normal then it goes warped and I haven't done anything.

Why would my internal soundcard, which works with everything from iTunes, Ableton to Audacity, be an issue all of a sudden?

did you figure out the issue? im having the same issues when i play in serato and not connected to any controller