macOS changes screen arrangement when waking from sleep
I have the same problem with my MBP running Mac OS 10.13.1. My non-Apple monitors are plugged into an OWC Thunderbolt 3 Dock using USB-C to Display Port and Thunderbolt to Display Port cables. So far, the only solution I have come up with is to keep my monitors awake. I am using a black screen saver to make the monitors go dark after 10 minutes. While this is not ideal, it does solve the issue of the displays changing places.