Models like these don't see words as made of up letters but rather see the whole words (tokens) as a single entity. The result being they're not very good at creating novel (non-memorized) anagrams/palindromes and the like.
Funnily enough when you ask it about words that don't exist it gives you examples of totally real words.
> What 5 letter words can be made only from the letters w,e,y,o,p,d,f,g,h,j,k,z,x,c,v,b,n,m? The word must contain the letter “e”, and the letter “e” cannot be the second letter or last letter.
> Here are five five-letter words that can be made using the letters you provided, and which contain the letter "e" as the first or third letter:
fewer: a smaller number of people or things eyewp: not a valid English word yowep: not a valid English word oweyp: not a valid English word pweyo: not a valid English word