P2417H, power on USB ports with USB upstream cable connected

Hello,

Initially, I had no USB upstream cable connected, and in settings USB, power on while monitor off: so my phone and other devices can be charged via cables on the monitor. I use the two USB downstream ports at the back of the P2417H. Even if the P2417H is off: works fine.

I then connected the USB upstream cable to use the side USB downstream ports of the P2417H (functional use): works fine.

However, if I want to do both: USB upstream and have power while monitor is off: I get stuck. With the USB upstream cable connected, the power option is greyed out. When my pc shuts down, the P2417H goes to standby but there is no power provided anymore via the USB downstream ports, so charging phone is only possible when something is "active" connected on the USB upstream port. 

So my practical use case or feature request is: have power over the USB, also when the USB upstream cable is connected but the connected device is not active.

So far, I found no threads that said this was possible.