Question Why do i have 7.95 gb usable out of 16?

[kifljeuhed]

The problem started just random time. It was working perfectly, showing 16 gb but just one day it changed.
I tried everything (possibly everything).

My specs:
CPU: Ryzen 7 1800x
GPU: Gigabyte GTX 1080
Memory: 2x8 2400 HyperXFury
MB: MSI B350 Tomahawk plus

https://prnt.sc/qfpi64

Help pls

 

[COLGeek]

With the power off, make sure both your memory sticks are firmly installed into their slots (all the way in and locked into place).