FX Loop 2 has strange crackling noise (no, it isn't clipping)

I am having the STRANGEST issue with my FX Loop 2. I am getting this nasty crackle, but when I turn the Loop off, the crackle goes away. The weird part is it a very repetitive, almost rhythmic crackling. It doesn’t really change with volume it alway crackles at the same pace. Like 8th notes of crackling

I know its the loop bc when I disengage it, the noise stops.

This is a pretty old preset that I have used for a while and havent changed much. Definitely havent changed recently, and definitely have not even touched the FX Loop. It crackle direct into my monitors and when I go through Logic. It just started out of nowhere and swear when I rebooted the system the first time, it didnt crackle, but only for a couple seconds. FX Loop 1 works just fine, too

The absolutely strangest part is that if I go to another preset (which is virtually identical to this one, just different EQs and different pedals) FX Loop 2 works fine. 100% HAS to be software related. But why it is only this one preset, I have no idea.

Anyone else experience anything like this?

Seems to go away if I move the loop before the cab, but still after the amp. Still confused though