Razer keyboard problems

hi guys , i recently bought this keyboard (razer blackwidow ultimate chroma) 2nd hand but i found an problem. Whenever i play games like call of duty or other games, i suddenly stop running or i double tap w when i just pressed it once. i read on internet it may be because its dirty but i cleaned the whole keyboard by watching a yt vid and after that it still does this. its basically impossible to play like this cause its so annoying i just stop running or whatever. Anybody who can help me ? i cant contact razer the warranty is outdated.