Getting errors in Memtest with RAM at XMP... (Maximus IX Hero)

[Raad11]

The RAM I'm using is G.Skill's F4-3600C15D-8GTZ (DDR4-3600, 15-15-15-35 @ 1.35 v)

When it's set to XMP profile (aforementioned 3600/CAS15 timings), I get errors in Memtest pretty quickly (Several within the first hour or two). When I run it at DDR4-2133, no XMP, there are no errors (at 2 hours and counting so far).

Does this mean the RAM is bad? Not reliable? It's in the motherboard compatibility list from Asus.

Could the motherboard have an issue?

Are there any settings in BIOS I could change to make it stable?

[Bahz]

Please note that even though there might not be a topic for this specific kit but XMP related issues has been discussed in hundreds of topics on this forum. I won't post a thread for you as I hope you can try searching it yourself, there's a reason why we made the search bar the main focus on the front page. You can definitely post your question in any of those threads and there are a ton of experts on the forum that can give you some pointers on what you're doing wrong. Thanks.