Permabanned
Reality is there is i gain from CL14 not big one at lest.Well, I am not too sure about the x470 motherboards Agesa versions. But with X570, There is a bug if the Infinity fabric is running higher than 1800Mhz. It might be causing your test to fail and not the CL14. Agesa 1.0.0.3ab fixes this, but, will that come to x470 motherboards?
Second You should run your memory at 3733Mhz CL17. According to AMD that's the ideal setting for 1:1 ratio with the Infinity Fabric running at 1867Mhz.
You might have better luck running your memory at 3600Mhz if you really want to use Cl14.
EDIT: This is what I get when I write post so late at night. I mess up. On the x470 motherboards the Infinity Fabric and the Memory speed decouple after a certain speed to prevent crashing. The bug only applies to x570 chipsets.
Which leads to the question, are you gaining anything in performance by running memory higher than 3600Mhz on older chipsets? It's 1:1 ratio when it's coupled but divides 1:2 after 3600Mhz.