Multiple forms in django
Somewhere on "Stack Overflow" was question like your.

Main idea was remove None from form initialization.

if "change_name" in request.POST:
    change_name_form = ChangeNameForm(data=request.POST, instance=request.user)
    if change_name_form.is_valid():
        change_name_form.save()
        name_message = 'Your name has been changed.'
else:
    change_name_form = ChangeNameForm(instance=request.user)

if "change_password" in request.POST:
    change_password_form = PasswordChangeForm(user=request.user)
    if change_password_form.is_valid():
        change_password_form.save()        
        password_message = 'Your password has been changed.'
else:
    change_password_form = PasswordChangeForm(user=request.user)

if "change_email" in request.POST:
    change_email_form = ChangeEmailForm(request.POST, instance=request.user)
    if change_email_form.is_valid():
        ...
        email_message = 'Please click the link in your email to confirm changes.'
else:
    change_email_form = ChangeEmailForm(instance=request.user)


This is my solution. I hope it's help you.