That's totally understandable. If you're not using XMP and haven't enabled it in the bios, you won't run the ram at full speed anyway. Here's an article mentioning that you have to enable XMP to unlock speeds even at 3200:
https://www.pcworld.com/article/394794/how-to-enable-xmp-to-run-your-ram-at-full-speed.html
I hope that helps.