This question comes up frequently. If you think about it for a few moments, how likely would it be for the Mint to make the same "mistake" on hundreds of millions of coins struck over a 14-year period without fixing it? The explanation is that it's NOT an error, just artistic license.
In the 1920s it was a common affectation for artists to use the Latin alphabet for items that were designed in the Classical style. Latin doesn't have the letter U; V was both a vowel and consonant like our use of the letter Y. You had to figure out the sound from the context in which the letter was used.
Both dollars and quarters from that era used the Latin spelling so they both read TRVST. In addition many buildings and other artwork from that era were all lettered with the Roman alphabet.