Keys.chord(Keys.ENTER) adds extra character in firefox


i have a test scenario where i use the following lines of codes:
WebUI.setText(to, text)

this is used to enter text into a text filter and then search for the entered value, there is no alternative for the search.
everything works as expected in Chrome, but when i do this in firefox i get an extra character together with Keys.ENTER, in my case i always get ‘B’, is there any workaround to this or a better way to send enter to a textfield in firefox?