2 RAM not working. Please help

[Hiatus444]

Hi! Thanks in advance guys. I have here an issue with my newly bought ram. My mobo has 4 slots, I currently have 1x Hyper X 8GB ram 2400Mhz that is perfectly working. 

 When I bought and inserted my 2nd ram(exactly same frequency and model/brand). The PC just doesn't boots at all(I also followed the hierarchy of ram instructed by the mobo's manual). Tried reseating it all and still doesn't work on dual channel. 

Also tried putting just the new ram on the current working slot and it doesn't work.  So I tried to return it to the store I bought it to, but surprisingly, it works perfectly with their mobo. Do I need to try to update bios or any recommendation you guys have? Thanks again, guys.

 

My pc specs is:

Intel G4560

MSI b250m Mortar

Sapphire rx580

500Watts PSU.