who makes the *best* cat6 plugs?

I have been running and terminating wire for a very long time, but it's never been the main job I do. So I know some things but I'm coming from a place this isn't really in my wheelhouse necessarily.

• I have a 4p/6p/8p terminator tool, so old any info printed on it has long since rubbed/scratched off it. I bet this is 10+ years old but has 'normal wear and tear' nothing is particularly broken. I realize this could be the whole root of the problem and am hoping to rule it out. It's probably older than the cat6 standard, but RJ45 is RJ45 on the outside. A new Klein is a trip away if it's needed but I'm not 'supposed' to just go buy myself a new tool to fix this.

• I have been using Monoprice cat6 wire for years, our company buys boxes of it 10 at a time, usually have 2 or 3 colours on hand so I can pretty well say I could certainly have a bad box, or a bad internal cut on one pair within, but it's not 'bad wire' categorically.

• We (well I, I don't go through supplies often so I usually just grab a handful of whatever our current stuff is) have the Monoprice cat6 ends with the inserts. I don't love these ends. They aren't the worst to work with, the wire through ones would be easier but these are the next easiest, but I don't know if that comes with caveats.

• I'm getting a lot of crimps with 3 pair fine and one (usually green, everything we do is A spec) open or intermittent. I'm thinking because it's on the end its either the die isn't crimping it hard as the others, or the insert inside the plug isn't aligned quite right for everything to make contact.

• I am hoping I can get a recommendation of the best cat6 ends, the best for the money, etc. and fix some of the existing bad crimps proving it's not the wire. If not it gives me pretty good footing to get new crimpers and hopefully for the whole crew. Lot less costly than having the crew come back and pull all these wires a second time.

Thanks in advance.