IssueTracker

In SwappyDisplayManager.java you are comparing apples and oranges, it seems.

Reading about the DISPLAY_MODE_RETURNS_PHYSICAL_REFRESH_RATE we get to know that Display.getRefreshRate() will always return the app frame rate whereas Display.Mode.getRefreshRate() will return the physical display refresh rate on Android 12 and later.

This is the current logic:

@Override
    public void onDisplayChanged(int displayId) {
        synchronized(this) {
            Display display = mWindowManager.getDefaultDisplay();
            float newRefreshRate = display.getRefreshRate();
            Display.Mode newMode = display.getMode();
            
            boolean refreshRateChanged = (newRefreshRate != mCurrentMode.getRefreshRate());

I'm suggesting the following fix:

@Override
    public void onDisplayChanged(int displayId) {
        synchronized(this) {
            Display display = mWindowManager.getDefaultDisplay();
            Display.Mode newMode = display.getMode();
            float newRefreshRate = newMode.getRefreshRate();
            
            boolean refreshRateChanged = (newRefreshRate != mCurrentMode.getRefreshRate());

Obviously, I haven't tested this. Just want to highlight a possible flaw. Please look into it!