The issue isn't with XMP itself, but rather something else is preventing it from functioning.
The issue isn't with XMP itself, but rather something else is preventing it from functioning.
You recently bought a new motherboard but XMP isn't activating. You've checked the BIOS for manual voltage and timing settings, but it's just restarting with default 2133MHz. It seems to jump in and then settles at that frequency. Your specs include an Asrock B450M, Ryzen 2600X, Corsair PSU, and a 3600mhz kit. Have you considered other options or might you need to return it?
You could simply reset the system using CMOS and then apply XMP settings.
You've successfully reset the CMOS a couple of times. Now you're left with just one choice: retry or request a return.