AW2725DF, unable to detect display signal

Recently purchased AW2725DF but the monitor unable to detect DP / HDMI signal if I restart my pc or fresh power on?

After some troubleshooting, I found out that I need to unplug the DP cable before power on my pc. Once the pc is switch on, the VGA q-led will light up (probably due to no cable connect to GPU?), then I plug in the DP cable and the monitor will work fine (VGA light still on).

I tried on my other Dell monitor but does not have such issue.