Okay, I make an sample test, first test case open katalon web page and click Sign In
WebUI.openBrowser('')
WebUI.navigateToUrl('http://forum.katalon.com/')
WebUI.click(findTestObject('Page_All Categories - Katalon QA/a_Sign In'))
WebUI.delay(5)
WebUI.callTestCase(findTestCase('login'), [:], FailureHandling.STOP_ON_FAILURE)
Second test case fill input fields and click Sign In
WebUI.setText(findTestObject('Page_Katalon Studio Best automated/input_user_email'), 'dummy.user@dymmy.com')
WebUI.setText(findTestObject('Page_Katalon Studio Best automated/input_user_pass'), 'dummypassword')
WebUI.click(findTestObject('Page_Katalon Studio Best automated/input_login-btn'))
In Firefox it works fine when you run it in new session but if you try to run these tests in opened session it fails because filling input fields (Email and Password) fails. setTex seems to work fine but nothing appears in the fields.
And this problem is in Windows 10 + Firefox