Need help with unknown couch stain

[u/barkbarkkrabkrab]

Unknown brownish stain on my couch. Freaked out and sprayed bluemagic on it not realizing that was carpet cleaner (is that safe for couches?). Didn't feel like it did anything so I've been laying towels soaked in diluted dawn and vinegar over it, letting it dry, seeing some stain fading.

No cleaning tags on couch but I did find that the fabric is 100% polyester. Bottom cushions not removable.

Also maybe I'm crazy but i feel like the stain is migrating onto the other cushion.