Harmonizing with chordtrack often fails

Hi, I’m experimenting with the audio harmonizer in Cubase 10 and sometimes it worked but mostly the harmonizer doesn’t follow the chordtrack as it should.
A lot of times the vocals don’t react at the same right moment on the chord change. Sometimes a few seconds later or they ignore a chord at all. (Just normal simple chords and I tuned the original vocaltrack via vari-audio before I did the harmonization. Can anyone help me with this please? Thank you so much!

Problem solved. The melody was sung often before the beat so I had to move the chords a little forward too