Bug sendKeys TAB

browser : firefox
WebUI.sendKeys(to, Keys.chord(Keys.TAB)) function inserts special characters in the fields

FYI, you only use Keys.chord() if you are trying to send multiple key presses simultaneously, for example, when you want to use modifier keys like ctrl + c.

With this in mind, try just sending the tab key itself:

WebUI.sendKeys(to, Keys.TAB)