Cryptogram - Quote Puzzle

At level 13 i solved it, but it wouldn’t unlock the next level. I even tapped on ever letter possible and entered the corresponding letter to solve the quote.

Im at Level 739 — around 300 or so all of a sudden, the letter boxes either don’t show up or they stay on the entire time, even when I move to another letter. It’s rather annoying & causes me to take 3 times as long; I either have to do a bit more sleuthing to figure out which word is missing a letter, in order to trigger the end of the level. Also — it would be fantastic if you could make the letter box advance automatically to the next letter, instead of having to constantly tap every time I fill in a letter. That would be great. Other than those things - this is one of the best crypto apps I’ve found — mainly because A. You have dark mode and B. So many levels that I don’t have to pay to play. Cheers