Once again solved my own issue
From what I gather, it's a bios bug.
Here's the solution:
.Go into your bios.
.Go to the overclocking menu and go to the CPU section.
.Change your overclock settings from "all core" to "specific per core" NOT regular "per core".
This is bios version 1.80.
That should fix it.
I'm now getting a flat 5.1ghz while running prime95 v26.6 like I should anyways.
If you change it to just the regular "per core" setting, interestingly enough the problem gets weirder. It starts staying a 4.7 at idle and then goes up to 5.1 under load, but still periodically drops to 4.7 so still no good. It looks like Asrock needs to do some bios updates.