Alexa.ChannelController.ChangeChannel odd behaviour

I am encountering odd behaviour from the Alexa ChannelController.ChangeChannel directive when recognising some UK channel names:

Utterance -> Payload

"BBC 1" -> { channel: {}, channelMetadata: { name: 'BBC 1' } }

"BBC 2" -> { channel: {}, channelMetadata: { name: 'BBC 2' } }

"BBC 3" -> { channel: {}, channelMetadata: { name: 'bbc three' } }

"BBC 4" -> { channel: {}, channelMetadata: { name: 'bbc four' } }

"BBC 5" -> { channel: {}, channelMetadata: { name: 'b. b. c. five' } }

"BBC 6" -> { channel: {}, channelMetadata: { name: 'b. b. c. six' } }

and horror of horrors (!):

"BBC radio 4" is not recognised as a valid channel (nor any other "BBC radio X" format names).

Questions:

a) Why is the BBC TV channel payload inconsistent? b) Will this behaviour persist? c) When will BBC radio channels be properly recognised as valid channels?

Note: Language is UK English and the Lambda function is hosted in EU West (Ireland).

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