M3 Pro display conflict: macOS locks out the second identical ASUS monitor based on connection order
Hey guys,
Need help with a weird display conflict on a MacBook Pro M3 Pro. I'm trying to run 2 identical external monitors alongside the built-in screen, but macOS only allows one to work at a time based on which one I plug in first.
Hardware setup:
• MacBook Pro (M3 Pro chip)
• Monitor 1: ASUS VP228HE (via built-in HDMI)
• Monitor 2: ASUS VP228HE (via USB-C to HDMI adapter)
The exact issue:
Whichever monitor I plug in first works perfectly. But as soon as I plug in the second one, it gets completely ignored (No signal / Black screen) and doesn't show up in System Settings at all.
If I unplug HDMI, the USB-C monitor immediately turns on. If I plug HDMI back in, the USB-C one stays on but the HDMI one now gets ignored. It's a "first come, first served" lockouts.
Since the monitors are strictly identical clones, it seems macOS caches the EDID of the first connected monitor, and then blocks the second port because it thinks it's a duplicate hardware conflict.
Is there any workaround or terminal bypass to force macOS to handle identical EDIDs independently based on the physical port, or am I forced to buy a hardware EDID emulator / DisplayLink dock?
Thanks!