Turning off my android phone screen without actually turning it off

I have a problem with my J7 Pro(SM-j730F) when i power off the screen and then turn it on again it flickers and takes a bunch of turning on and turning off(Pressing the power button or using fingerprint then pressing the power button again) tries to get it working again, And when it finally turns on i'm good to go aslong as i don't turn my screen off again. What i want is: To be able to lock my screen without it actually being turned off. And i have tried Always on display to keep the screen on but the reason it doesn't work is because there is like a frame where the screen turns off completely before it goes to Always on display, So something similar to Always On Display would be great but without the part where it turns off for a frame.