Ok. I solved it.
So if anyone interested you can try this:
I am using them with ASUS X670E-E, latest bios 1416 and 7950X3D CPU. Default EXPO I/ EXPO II settings didn't work and this caused boot and stability issues. So what you can try: 1.Set Fast boot to disabled. 2.Set Memory context restore to enabled. 3.Set VDDSOC voltage to manual and set it for 1.27v for example. It is limited to 1.3 maximum so no worries. Vsoc voltage can impact dram oc stability. 4.And the most important try to increase DRAM VDD and DRAM VDDQ voltages. These RAM modules use Samsung IC chip so it is safe to keep VDD voltages between 1.10 - 1.40V and VDDQ voltages between 1.10V- 1.50V. Corsair support agent confirmed they are safe! I set mine both to 1.40V but you can try slowly increase from default 1.35V. After that mine system is stable. Tested with AIDA64 and other different tests showed system is stable.
