I'm seeing the same thing. Options for PE are PE, PE Flex, and PE Fully-Flex. PE Flex says "fully refundable before departure" and PE Fully Flex says "Fully refundable at any time". Selling class is T if I select "Premium Economy Flex" and is listed as an Online only fare.

PE Flex comes with seat selection and in the fare rules shows refundable until departure.

Interestingly the fare rules on a Fully Flex ticket show refunds are not permitted after your first flight has departed or for no shows on the outbound (USA to UK), but refunds are for both scenarios from the UK to USA. Makes no sense.