Cycling Problems

[Lee Marlin]

Hello, I have a problem I can't seam to figure out. I built an AR with a palmetto arms upper in 6.5 Grendel. It has a mid length gas tube and a 20” bbl. I had an adjustable gas block but I replaced it with a standard one. My problem is Factory ammo ( Hornady american 123 BTHP ) cycles fine. But when I make hand loads it will not cycle. I have even went over book max with several powders, AR COMP, H322, and H335.
Everything I've read says it should cycle with a standard buffer. Any suggestions would be helpful. Has anyone else had this problem?

Thank you in advance.