AutoIt will not send key strokes

Question

I am trying to get a small script to change the default web browser to Chrome on a Windows 10 machine. For some reason it will not send the keystrokes. It will only perform the first MouseClick.

MouseClick("left",270,877,1)
_WinWaitActivate("Cortana","")
sleep(1000)
Send("defa{ENTER}")
sleep(1000)
_WinWaitActivate("Settings","Settings")
sleep(100)
Send("{TAB}{TAB}{TAB}{TAB}{TAB}{ENTER}{TAB}{TAB}{ENTER}{ALTDOWN}{ALTUP}")

I do have the winwait function created as well as a key delay.