I can't increase cas latency above 13 on my ga-z170-hd3 ddr3 motherboard

[wzrd]

My system:
i5-6400
GA-Z170-HD3 DDR3
RAM 1. 8Gb DDR3-1600 Samsung M378B1G73EB0 - with this memory stick no problem, i'm overclock it at ~3170Mhz 17-17-17 1.5v
2. 8Gb DDR3-1600 Samsung M378B1G73DB0 - but this stick, i cant increase cas latency above 13, even at 1600 MHz, motherboard beeps and resets settings. The maximum frequency overclocked this stick - 2700MHz 13-16-16, but with this timings the system is unstable.


What did I do?
1. flashed different versions of BIOS, including BIOS from the clone motherboard GA-Z170-HD3 (with DDR4 slots) - this did not fix the problem.
2. Rearranged memory in different slots, leaving only one stick. - M378B1G73DB0
3. checked this memory stick (M378B1G73DB0) on another motherboard (ASUS P7P55D) - no problems detected, it worked fine for 2000mhz 15-15-15 timings (max for ASUS P7P55D).
4. Fast Boot enable\disable.

Can anyone explain what is the reason for the inability to increase (increase! not decrease) timings? bios bug? incompatibility?
PS Sorry for my english.

 

[INSTG8R]

2 different sticks. Dual channel will always default to the slowest stick. Outside of that maybe it just can’t handle it.