R9 280x resolution changes automatically

[Pastafrulem]

Computer Type: Desktop

GPU: Sapphire R9 280X, no overclock

CPU: i5 4690K, no overclock

Motherboard: Gigabyte z97x-SLI

RAM: 8 GB

PSU: Corsair CX750

Operating System & Version: Windows 10

Description of Problem: Almost once a day the resolution changes automatically without me doing anything in particular, it goes from 1920x1080p to 1600x1200p. It happens while im doing "simple" things (browsing the internet, using word, excel, etc). Another problem i have is that when i try to open a game (cs go for example) the screen starts flickering and the pc freezes , in this case i have to close session, change resolution back to 1080 and start all over again. When i try to open it after this it all goes fine. Neither of these pproblems has happened while gaming.

 

I've tried uninstalling all GPU drivers and instaling them again, all cables are properly connected and the temperatures are were they should be. This started 6 or 7 months ago.