Button NIL even though Get returns the Button

[aaronfranco]

 let url = URL(string: "http://192.168.2.5")!
        open(then: .wait(10.0))(url)
    >>> get(by: .id("UserName"))
    >>> setAttribute("value", value: "xxx")
    >>> get(by: .id("Password"))
    >>> setAttribute("value", value: "xyz")
    >>> get(by: .class("submitBtn"))
    >>> press(then: .wait(10.0))
    === { (apage: HTMLPage?) in
            print("\(apage)")
        }

this returns "nil" and I cannot figure out why. When I look at the logs, it says the node was nil.

SCRIPT
getElementByXpath("//*[@id='UserName']").setAttribute("value", "xxx"); document.documentElement.outerHTML;
[.]

SCRIPT
getElementByXpath("//*[@id='Password']").setAttribute("value", "xyz"); document.documentElement.outerHTML;
[]

nil

The following code fetches the submit button just fine, which is why I'm surprised the snippet above doesn't work. What am I missing?

 let url = URL(string: "http://192.168.2.5")!
        open(then: .wait(10.0))(url)
    >>> get(by: .id("UserName"))
    >>> setAttribute("value", value: "xxx")
    >>> get(by: .id("Password"))
    >>> setAttribute("value", value: "xyz")
    >>> get(by: .class("submitBtn"))
    === { (apage: HTMLElement?) in
            print("\(apage)")
        }