Does it have a rifle stock?

Nope, carbine receiver extension.  But I was told, I think in this thread, I'll have to go back and look, that that's what I should use.

ETA:  can't find it in this thread so it must have been somewhere else.

If the spring is too long it can coil bind and not allow the bolt to cycle all the way to the rear and lock back nor pick up the next round off the stack.  Can you lock back the bolt manually?  Even if if the bolt does lock back manually, too much of an increase in spring rate can slow the bolt from normal function.  Are you using a standard 308 buffer?

I can lock the bolt to the rear manually.  I believe I have a standard 308 buffer.

Unless it's some proprietary receiver extension/bolt carrier/spring/buffer combo, I'd put a carbine spring and carbine H, H1, or H2 buffer in it and fire mags with a single round to check for LRBHO. If it's slinging brass to the 4 o'clock you can increase buffer weight or put in a stronger spring, but as others mentioned a rifle spring and/or buffer might be leading to cycling issues on their own. If it's failing to eject, LRBHO, and/or dribbling brass out you can try a lighter buffer.

Issues like these are why I like having an AGB. I dial it open until I get LRBHO and if I'm getting sooty brass from a suppressor I can increase the buffer mass to have the action stay locked a touch longer.

I’ll try the recommendations.

Just checked - A5 tube, Sprinco green spring, H3 carbine buffer.

Have you tried Lancer mags?  I had this problem with the 350 makers and this seemed to fox it for me.

Has anyone had feeding issues with the Maker 350 grain bullets and lancer 10 round mags.? I have my COAL at 2.80 and 2.77. If I have more than 2 rounds in a lancer mag the round feeding into the chamber pops up  when releasing the bolt and hangs up.

I don't  have this issue with Gorilla 285 grain fracturing bullets or Barnes 210 TSX. They feed just fine whether 2 or 10 rounds are in a lancer mag.

will try some of my 20 round PMAGs next time out. Just curious if anyone has seen the same issue with lancer 10 rounders.