I was going to say could be the offsets are a bit off...but...after listening to it a couple times and seeing the video...hmmmmm.....cause it sounds like the consenents are fine
To me I feel like the main issue with CV banks is that there's no proper method to blend the "a i u e o n" sounds without massive editing. when you want it to sound natural like "ku nai" or "ho n" ....only thing I can think of to work around that is to make a new allias for the vowels call it
" i 1 "
"a 1"
or
" i ble "
"a ble "
and have the green line a lot higher than normal but still within the pink area....like almost to the point where don't hear the beginning of it starting but can still hear the sound (trying to think of the musical term where it's soft at the beginning but gets louder)
But other than that I really like your utau ^^