Scan for malware. Be sure to try the keyboard with NO DRIVERS but what Windows has.
So some of the keys on my Razer black widow tournament edition stopped working a while back. The "Esc,F,U,Tab" keys. Yesetrday while playin g fortnite I decided to plug it back in. The keys WORKED! They worked fine for the rest of the night until I booted up CSGO then the keys stopped working again?? I'm so confused, anybody know the issue?