It would help to know what device(s) you have tested on, along with what OS version(s) you are testing on.
Any reason you need to use "keyup" vs "change"? Does the email field need to be updated on every single keypress?
I want to achieve the following:
a user writes in a textarea and when he wants he can copy to clipboard that text, so i think the variable needs to be updated real time onkeyup, right?