The cryptogram decodes to a string of phonetic names of English letters.
cue es double u aitch kay cee ar ZRW WH VKRMCW R OBQZS XOF ZWW ON cue bee kay u bee aitch ar en ZRW MWW XOF R MWW OBQZS ON WU double u cue es en o aitch VKRMCW R ZRW WH WU K OBQZS
This string can be decoded using the same substitution cipher (and in fact, the most likely solution path involves using this second layer to help on some of the more ambiguous letters in the first layer, such as ES and EN).
thesolutionisurethras QSWHKCRQBKUBHRNWQSNOH
URETHRAS is the answer.