Welcome to the site!
Many years ago, the Alaska State Police carried the S&W 4006. I was told by at least one trooper that he had to keep his gun well-lubricated at all times if he wanted reliable performance. Especially if your gun had not been shot much by the previous owner, I'd recommend treating it like a new, not-quite-broken-in-yet handgun; keep it well-lubed, and shoot full-power ammo in it (whatever brand/type you can most easily afford), at least until it's been shot a couple hundred rounds. Then try the other stuff again and see how it handles it.
Personally, I wouldn't pass judgement on the reliability of ANY autoloading pistol based on just a few mags of ammo.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)