ive tries all the suggestions and they are not the answer. sounds like a programming issue. is it the latest version or samsung products. never had problem befoe samsung. it needs a fix.
I assume the OP means how long the lockscreen stays on before it times out, which can be different from the screen timeout after the screen has been unlocked. In the past, I've seen it mentioned that power-saving modes and Smart Stay can affect this. Is that among all the suggestions you've tried? Or have you tried every suggestion in the known universe?