macOS seems to have a problem with USB-C external monitors. My resolution is 4K, scaled up slightly to accommodate bigger text.

When it awakens from sleep, the monitor resolution is "wrong". When my monitor wakes up, it is set to 4K, but the mouse moves as if it's in 1080p. In other words, it thinks the boundaries of the screen are 75% smaller than what exists, so I can't click on the "correct" thing, move windows, etc. I'm essentially forced to reboot.

I have both a Dell and HP z34 4K monitors.

The former used DP to USB-C, the latter uses just a USB-C cable.

This problem has occurred with 2 different monitors, cables, resetting NVRAM/SMC, and a fresh OS install (10.3 and 10.14.1).

Any suggestions?

  • It's actually still DisplayPort. Are you using the cables that came with the monitors or a 3rd party? – Allan Jan 11 at 21:07
  • The ones that came with the monitors – MrBradford Jan 14 at 16:18

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