pink bourbon v60 help!

coffee in question: tandem columbia faver ninco (a washed pink bourbon).

grinder: fellow opus (so far, using between 7-9)

water temp: 196-198

ratio: 21g beans to 300g water

recipe: 45g bloom for ~40 seconds, pour to 170, wait, pour to 300 pulsing as needed (i'm using a small plastic v60)

muddiness! so much muddiness! first brew time was nearly 4mins. i know pink bourbons are acidic but my first cup, at a 7 grind, was undrinkable. when i used the 9 setting my paper was STILL full of fines but i had gone too far... the coffee tasted totally empty.

i'm extra confused bc 7-9 is a rather coarse setting on an opus and from the tasting notes / reputation of pink bourbon i'd expect to be a lot finer.

my best guesses: less agitation, maybe center pour?

ADVISE🤗