I ended up creating a memtest USB drive and running it on my system. My BIOS settings were incorrect for my RAM (voltage was too low) and I thought resetting the BIOS would fix these errors but after repeating the memtest on all sticks I immediately saw more errors (2000+ in 30 seconds).
Now, I'm running the memtest on each stick individually. So far I've had the first stick throw errors, the second stick had 0 errors, and the third is ongoing but so far so good. Does this mean I can rule out CPU, L1, and L2 cache errors? And inversely, can I conclude that the first stick is what was causing errors, assuming the other 3 end up with none?
I plan on returning the faulty stick to amazon and getting a new one. Once I've installed it is there anything else you would recommend I check regarding system stability? Thank you for the suggestions so far, BTW! I never would have thought to check my memory...
UPDATE: The rest of the sticks produced 0 errors individually as well as together. Using Unraid now seems much more stable and I haven't encountered anything suspicious so far. Will report back with problems if I find any in the near future.