iPhone remote not bringing up a keyboard for apple tv

I am trying to use the remote on my iPhone 12 to enter my YouTube password on my Apple TV. Normally when I do this a keyboard pops up to allow me to enter the text. Today no keyboard appears. How can I fix this please? I have updated the Apple TV software, and restarted the iPhone 9its running the latest iOS. Does not work with my iPad either.

thank you for any help you can offer.

richard