Screen doesn't go in sleep mode

Hello, my monitor doesn't go in sleep mode. Although I set 1 minute, screen become black but it wake up after 3 or 4 seconds. I tried fedora (plasma 5.17 too) and everythings go well, so i think it's manjaro related. Any advise?
I'm on latest manjaro kde 18.1.2 but i had same problem in previous version of manjaro.
PS: tried manjaro cinnamon edition, screen goes in sleep mode

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