PSA: Check your filament before loading in the Core One

Got my new Obxidian HF 6.0 in yesterday, installed it and ran a massive decorative print with some PET-CF just because I can now. Many many hours later the print finishes flawlessly (this thing smokes the Bambus imo) I unload it, I load in the Galaxy Black Prusament that came with the Core One and it immediately starts clicking and grinding going in. I know from my Voron days that either means idler tension issue, stripped gears or a clog...

So I heat it up, poke around with a needle, no luck.

I switch out the nozzle, same thing,

I open the gearbox, everything looks peachy.

I check the filament path under the idler.... Looks okay I guess, my first Core One, I don't really know.

After several hours of messing around thinking the PET-CF must have wrecked my brand new printer in some way I can't figure out I noticed the cut on the Prusament was pretty blunt. On a whim I angle cut it with my snippers. Problem solved. It was the stupid filament the whole time. The Core One, or at least my Core One, is really picky about the feed end of the filament.

As a bonus I was having horrible resonation during long print moves and now that appears to be gone. It can't have been anything I did at the hot end. I only touched that and the top panel, and it's not the plastic top that was resonating. So eh, gremlins. The Core One is haunted. But despite that, it's the best printer I've ever had the pleasure of debugging.