Screen goes black on startup on macOS with retina screen

[blurpy]

Screen goes black for a couple of seconds when starting the emulator, like if it tries to change mode. Then it returns to the desktop and everything works as normal. Does not happen if a second monitor is connected, no matter if the window opens on the retina screen or the other screen.

From experimenting in Window.cpp it seems to happen in the line SDL_CreateRenderer(). Returning before that line results in no black screen, but also no window. Have tried different parameters in both SDL_CreateWindow() and SDL_CreateRenderer() but have not found anything that changes the behavior.

Google searches seem to suggest there are many who have issues with a persistent black screen with SDL and OpenGL on macOS, but I don't use OpenGL and it's not persistent, so must be something else.

This does not happen on Windows or Linux.