Excel freezes after using macro that sends email using Collaboration Data Objects

I use a macro to send out emails, I am using this approach: http://learnexcelmacro.com/wp/2011/12/how-to-send-an-email-using-excel-macro-from-gmail-or-yahoo/

Everything works fine, except that after the email is sent Excel will freeze. It is only the things that are visible in the document that are "frozen". If I scroll down or switch sheet, it will update the screen.

For example if I delete a row, it will delete the row but not show it on the screen. If I switch to another sheet and back again, it will show the row has been deleted.

Is this some kind of memory problem or what can cause this?

I am using the latest version of Windows 10 (1903 i believe) and latest version of MS Excel.

When I close and re-open Excel everything is back to normal.

This is the code from the link:

Sub SendEmailUsingGmail()

    On Error GoTo Err

    Dim NewMail As Object
    Dim mailConfig As Object
    Dim fields As Variant
    Dim msConfigURL As String

    Set NewMail = CreateObject("CDO.Message")
    Set mailConfig = CreateObject("CDO.Configuration")

    ' load all default configurations
    mailConfig.Load -1

    Set fields = mailConfig.fields

'Set All Email Properties

    With NewMail
        .Subject = "Test Mail from LearnExcelMacro.com"
        .From = "email@gmail.com"
        .To = "email2@gmail.com;email3@gmail.com"
        .CC = "email4@gmail.com"
        .BCC = ""
        .textbody = ""
    End With

    msConfigURL = "http://schemas.microsoft.com/cdo/configuration"

    With fields
        'Enable SSL Authentication
        .Item(msConfigURL & "/smtpusessl") = True

        'Make SMTP authentication Enabled=true (1)
        .Item(msConfigURL & "/smtpauthenticate") = 1

        'Set the SMTP server and port Details
        'To get these details you can get on Settings Page of your Gmail Account
        .Item(msConfigURL & "/smtpserver") = "smtp.gmail.com"
        .Item(msConfigURL & "/smtpserverport") = 465
        .Item(msConfigURL & "/sendusing") = 2

        'Set your credentials of your Gmail Account
        .Item(msConfigURL & "/sendusername") = "email@gmail.com"
        .Item(msConfigURL & "/sendpassword") = "********"'Update the configuration fields
        .Update

    End With
    NewMail.Configuration = mailConfig
    NewMail.Send
    MsgBox ("Mail has been Sent")

Exit_Err:

    Set NewMail = Nothing
    Set mailConfig = Nothing
    End

Err:
    Select Case Err.Number

    Case -2147220973  'Could be because of Internet Connection
        MsgBox " Could be no Internet Connection !!  -- "& Err.Description

    Case -2147220975  'Incorrect credentials User ID or password
        MsgBox "Incorrect Credentials !!  -- "& Err.Description

    Case Else   'Rest other errors
        MsgBox "Error occured while sending the email !!  -- "& Err.Description
    End Select

    Resume Exit_Err

End Sub