Test work properly on Chrome, not on Firefox

I wrote test using TestNG and selenium.

code...
actions.sendKeys(Keys.chord(Keys.CONTROL, "a"));
        actions.sendKeys(Keys.BACK_SPACE);
        actions.build().perform();
code...

I wanted to delete text in login window using these sendKeys, with DataProvider

@DataProvider(name = "inputs")
public Object[][] getData() {
    return new Object[][]{
            {"000000000", true},
            {"000000000", true}
    };
}

Test work as I expected on Chrome, but on firefox these sendKeys not always mark the text, and clear this text. In project I have to use action class. Why the test runs differently?