@EA_Kent I have the same problem too. did everything and noticed 2 things:
1.- I have 16gb of ram. with nothing open my ram is about 2.3 gb usage. after open apex only, I got around 7-8gb but after some matches it reach 12gb of usage. and I don't know why. there's a ghost process that runs with apex legends, but even without that issue, I have the same stuttering problem anyway. (I don't have 100% ram usage, just high but not enought to be a problem.
2.- I noticed I need the game with doble buffered or triple buffered, if I disable v-sync, the game consume 100% GPU usage I don't know why. but this is not the problem because I play with v-sync activated and I have a good spects to run it with that option.
I did everything on troubleshooting steps and nothing worked. It seems to be a problem on the game or anti cheat system is making performance issues.
and when I have stutterings, my computer performance it's ok. I mean, everything, temperatures, GPU/CPU/RAM usage it's ok.