Taste like “@@@“

I have a Mazzer Philos grinder and have made many delicious drinks from light thermals shocks to rich dark roasts but every cup I pour with the xBloom taste like ground cardboard thru a construction paper filter. Zero flavor. I have tried 35-65 on the machine grind and no real perceived difference. We purchased the xBloom to simplify morning coffee and it’s worse than Denny’s coffee (sorry no offense). Using fresh beans 10-21 days off roast, light to specialty dark (Starbucks blonde) dark. I had an inclination to try the flex lease and so far glad I leased as it’s going back unless I can get a good cup.