It's a 100% gas problem, then - it is NOT a recoil problem, at all. It's all in the gas.
You start an adjustable gas block WIDE OPEN. All the way, no joke, not kidding you. You get the gun WET, you break the gun in, THEN you start adjusting gas down to your desirable level. All those steps, in that order. That's the only way totune an adjustable gas block on a brand new build
If you don't start an adjustable gas block WIDE OPEN, full-on - then you'll never, ever know if the gas port in the barrel is even large enough in the first place - which is a proven issue on .308ARs. If you wide-open it on a broken in gun - and it STILL doesn't hold the bolt to the rear on a single round - that gas port needs to be drilled up, right then.
For now, stop looking at ejection patterns, and break the gun in. Get it wet, break it in, THEN play with the adjustable gasblock.
This is why we don't complicate shiit with complicated shiit.