Question ram Problem or what ?

Feb 18, 2019
I used to have a 2133Mhz 4GB ram already installed in my pc ,and now i bought another 4gb ddr4 2133Mhz ram of and when I added that ram into my pc,my pc seems to get stuck inside a restart loop after few minutes....both the ram sticks are showing in bios and there is no problem in identification of the two ram stick inside the bios,even my pc is starting normally with the new ram and it is also showing 8GB ram in properties but after runnig few minutes the pc is restarting again ..then again after running few minutes its restarting again what i did was ...inside bios i dropped the ram frequency to 1866Mhz and now it is working fine without any restarts...but i want to run it in 2133Mhz can some one help me please !?
My PC specs are :
'i3 6100' CPU
'gigabyte B350M-D2v 'motherboard
4GB (2133Mhz)+ 4GB (2133) ram