External Monitor is detected but displays black screen on MBP 15" 2017

I have a 15" LTN156HL01 Lcd display which I turned into an external monitor by using a controller board. Here's the thing: It works perfectly on my PS4. It works perfectly with my brother's MacBook Air. It even works when connected to my Canon 80D. But when connected to my MBP 15" the backlight of the external monitor lights up but the image is totally black. However my Mac detects the screen... even if I change resolution, the problem persists. Then one day I tried to reboot the MBP in safe-mode and when restarted properly... Hurrah! the screen was actually working super fine. But when I unplugged it and replugged it... here we are again.. black screen. With these test, I realized that the monitor works, the controller board works fine and that it can be used with my MBP 15". The problem is not with the hardware, it has to be related with software or OS. If not, I cannot explain why it worked that time... What can it be? How can I solve it? Thank you in advance!