I have one in 350 Legend. I use a modified PMAG instead of the factory supplied metal one. Feed and function is great.
The bottom of your bolt body probably is milled out in a crude notch pattern vs. round the whole length. That is for the guns that use AR or AICS type mags.
I have a stainless American with the round bolt and rotary mags. Never had a feeding issue with that one.
Never had a chambering issue with just reloads. Never shot factory ammo.
Sounds like your gun might be heading back. They usually are efficient. Make sure they pay all shipping and insurance for both ways.
