Likely related to https://bugzilla.libsdl.org/show_bug.cgi?id=3051

On initial run, the macOS menu bar will not accept input until task switching away and back.  Apps also appear to not accept single clicks (but double clicks work?)

Only occurs on Catalina, I can't reproduce on Mojave (haven't tried pre-Mojave).  It doesn't matter what window flags are passed in.

Bare minimum example:

---

int main(int argc, const char * argv[]) {
    SDL_Init(SDL_INIT_VIDEO);
    SDL_CreateWindow("Test", 0, 0, 1024, 768, 0);
    SDL_Event event;
    do {
        SDL_PollEvent(&event);
    } while (event.type != SDL_QUIT);
    SDL_Quit();
    return 0;
}