X299 Designare EX missing XMP option with BIOS optimized defaults - How to re-enable?

[dhl]

When I use optimized defaults in BIOS, I lose the XMP option in MIT. I know my RAM is XMP capable because I have a custom BIOS setting with XMP enabled:

Take a look. Here's with custom BIOS settings:

https://imgur.com/l3xC7vG

This is what I get with optimized defaults loaded:

https://imgur.com/T2LD72f

I'm using the latest BIOS version F7c with an X299 Designare EX. I've searched all the settings and can't find anything that would affect XMP. What do I need to do to enable the XMP setting in BIOS?

Thanks!