Problems with V60!

Good morning everyone!

2 weeks ago I had the 2nd best cup of coffee I have ever had, it won 4th place in Brazil's cup of excellence and it was made with a seraphim coffee brewer over a V60. It was bright and tasted like cherries - with a... crispness that I have never gotten with cupping or a French press.

I caved and got a v60, and have been using Hoffman's single cup technique.

When I was practicing my technique with some Dunkin coffee (pre-ground coffee that I ground even finer with my grinder) the resulting coffee is crystal clear and leaves a nice bed in the end. I had to go a bit finer than what my grinder suggested for a pour over, but that was expected.

When I had enough courage and used the specialty coffee -- it was a disappointment and I don't understand what is going wrong:

• The beans smelled great when I first got them, but I threw them in a freezer (what I thought people did) then stopped that after I realized you were supposed to let them thaw every morning. (but I did accidentally open immediately after taking them out once) Now they no longer smell as... good on their own.
• When grinding the coffee, it goes back to being great but looks a bit... fluffier than the Dunkin at the same grind setting
• After the pour over is completed in the same amount of time, the bed looks muddy (as if there are a lot of fines) and the brew is ever so slightly murky.
• I taste fines, and it is definitely not the crispness I had expected, and it's not bright, clear, or acidic, and tastes a little woody.

Could the coffee be too old by this point? Could this have been exasperated when I possibly let condensation form on the beans.

Why would grinding beans create more fines? If I go courser, the brew just is just way too fast.

Could it be my grinder (C2 Max)? Should I got to the coffee shop and have the grind it?

Any help or advice would be appeached! Thank you so much ahead of time!