Why do windows or Spaces move around when my displays wake?

A display layout change during wake can cause macOS to move windows. If this happens only with BetterDisplay running, check features that reconnect displays or restore their layout and configuration. Test them one at a time to find out which, if any, causes the change.

Narrow down what changes

Look at any virtual screens, mirroring, layout protection, configuration protection and Reinitialize this display on wake settings you have enabled. Change one relevant setting at a time and repeat the same sleep/wake test. The additional display settings explain wake reinitialization. The virtual-screen settings explain virtual-screen behavior.

If you use a mirrored virtual screen, its wake behavior is a useful place to investigate. It is not an explanation for a setup with no virtual screens. Likewise, increasing the wake delay may move the time at which the problem occurs without correcting its cause.

If the cause remains unclear, export your preferences and test with the app’s default settings using the app reset procedure. If that resolves the problem, reapply the features you need gradually and repeat the wake test after each change. This helps distinguish a saved configuration problem from behavior that also occurs with default settings.

A full macOS display-settings reset is a separate, more disruptive operation. It removes system display configuration and other display data and requests a reboot. Read Reset All Display System Settings before considering it. Do not use the NVRAM-clearing variant as a routine window-placement fix.