Macro To Log Into Website: Can't Submit Webform

[ExcelActuary15]

Hi Everyone,

I'm trying to write a macro that will log me into a website (i.e. enter my username and password, then submit the webform). Everything runs perfectly until the macro tries to submit the form...at that point, it just refreshes the login page, rather than redirecting me to the "post-login" page. I'm confident that the username and password that the macro enters are correct, because I can manually press the submit button and it will log me in. This is the code, FYI:

Sub LogIn()


    Dim ieApp As InternetExplorer
    Dim ieDoc As HTMLDocument
    
    'create a new instance of ie
    Set ieApp = New InternetExplorer
    ieApp.Visible = True
    
    'assume we’re not logged in and just go directly to the login page
    ieApp.Navigate "https://www.nfl.com/login"
    Do While ieApp.Busy: DoEvents: Loop
    Do Until ieApp.ReadyState = READYSTATE_COMPLETE: DoEvents: Loop
    
    Set ieDoc = ieApp.Document
    
    'fill in the login form
    With ieDoc.forms(1)
        .UserName.Value = "****************@gmail.com"
        .Password.Value = "********"
        .Submit
    End With
    Do While ieApp.Busy: DoEvents: Loop
    Do Until ieApp.ReadyState = READYSTATE_COMPLETE: DoEvents: Loop
    
End Sub

I've also tried the following solutions, which haven't been successful:
.getelementbytagname("Input").Click
.all("Input").click

Any and all help would be appreciated. This is my first foray into html.

Thanks!