Chrome mobile emulation. Window size is different via Selenium and Devtools - selenium

Question

Need to test web site responsibility.
Code example taken from here (in the bottom of page)
Faced, that selenium opens chrome window in different size/resolution, than i expect. Looks like that pixelRatio is not accepted or accepted incorrectly.
Also, faced, that in devtools, devices size from default device list is already divided on pixelRatio. e.g. Iphone 6 has 750 x 1334 and pixelRatio 2.0, but in devtools it is 375 x 667 which perfectly fits original resolution divided on pixelRatio. But if I manually add custom device 750 x 1334 with pixelRatio 2.0, it still shows me 750 x 1334
In source code Iphone 6 already defined with 'divided' size and pixelRatio 2.0
"title": "Apple iPhone 6",
"screen": {
"horizontal": {
"width": 667,
"height": 375
},
"device-pixel-ratio": 2,
"vertical": {
"width": 375,
"height": 667
}
Here is sample of my enum for mobile devices.
public enum ChromeMobileDevice {
IPHONE_8(1334, 750, 2.0, "Mozilla/5.0 (iPhone; CPU iPhone OS 11_0 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) Version/11.0 Mobile/15A5341f Safari/604.1"),
IPHONE_XS_MAX(2688, 1242, 3.0, "Mozilla/5.0 (iPhone; CPU iPhone OS 12_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/69.0.3497.105 Mobile/15E148 Safari/605.1"),
GALAXY_S8(2960, 1440, 4.0, "Mozilla/5.0 (Linux; Android 7.0; SM-G892A Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/60.0.3112.107 Mobile Safari/537.36"),
IPAD_MINI(2048, 1536, 2.0, "Mozilla/5.0 (iPad; CPU OS 12_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0 Mobile/15E148 Safari/604.1"),
GALAXY_TAB_10_1(1920, 1200, 1.0, "Mozilla/5.0 (Linux; Android 8.1.0; SM-T580) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Safari/537.36");
private int height;
private int width;
private double pixelRatio;
private String userAgent;
private boolean touch = false;
private ChromeMobileDevice(int height, int width, double pixelRatio, String userAgent) {
this.height = height;
this.width = width;
this.pixelRatio = pixelRatio;
this.userAgent = userAgent;
}
public static ChromeMobileDevice getByName(final String chromeMobileDeviceName) {
return Stream.of(ChromeMobileDevice.values()).filter(b -> b.name().equalsIgnoreCase(chromeMobileDeviceName)).findAny()
.orElseThrow(() -> new IllegalArgumentException(String.format("Unsupported chrome emulator name: %s", chromeMobileDeviceName)));
}
public HashMap<String, Object> getPortraitDeviceMetrics() {
return Maps.newHashMap(ImmutableMap.of(
"height", height,
"width", width,
"pixelRatio", pixelRatio,
"touch", touch));
}
public HashMap<String, Object> getLandscapeDeviceMetrics() {
return Maps.newHashMap(ImmutableMap.of(
"width", height,
"height", width,
"pixelRatio", pixelRatio,
"touch", touch));
}
}
UPD
Sample of chromedriver creation
ChromeOptions capabilities = new ChromeOptions();
capabilities.setCapability("chrome.switches", "disable-extensions");
capabilities.setCapability(SUPPORTS_JAVASCRIPT, true);
capabilities.addArguments("--hide-scrollbars");
capabilities.addArguments("--allow-running-insecure-content");
capabilities.addArguments("--start-maximized");
capabilities.addArguments("--disable-infobars");
Map<String, Object> mobileEmulation = new HashMap<>();
ChromeMobileDevice chromeMobileDevice = ChromeMobileDevice.getByName(chromeMobileEmulation.get());
mobileEmulation.put("userAgent", chromeMobileDevice.getUserAgent());
mobileEmulation.put("deviceMetrics", chromeMobileDevice.getPortraitDeviceMetrics());
capabilities.setExperimentalOption("mobileEmulation", mobileEmulation);
WebDriver driver = new ChromeDriver(capabilities );