Screen shuts off when convergence dock plugged in

[Lodj]

PostmarketOS convergence edition phone. Software fully up to date. Plugging in the dock shuts off the screen immediately, no matter what is in (or not in) the dock, even if it's empty. Unplugging it immediately restores the display.

When plugging in a basic 4-port USB3 to type C hub I had laying around, the screen dims significantly. Thinking perhaps the screen shuts off when power draw is too high I plugged an LED keyboard into that USB hub, but screen brightness did not change, the keyboard just lit for a moment then shut off.

[Lodj]

This turned out to be an issue related to the backlight voltage rail / data bus issue, you just have to set the backlight to at least 50% brightness before plugging in a USB device.

The USB device also doesn't always work, but that seems to be somewhat a matter of luck