Cubases feature of making harmonies doesn't sound good

Hi guys,
I have been playing with Cubases feature of making harmonies from an audio songtrack. The lines it chooses are fine, but I am very disappointed with the robotic and synthetic sound it produces.
It’s strange, since another Cubase feature - the transpose track - works very well with audio, and I would suppose it’s using the same algoritm.
Am I doing something wrong - or is this the best, Cubase can do ?

Until I understand, that is normal. The changes in pitch are too big, so an unnatural sound should be expected. But I have seen some people use the feature for testing vocal harmonies or to build background vocals. In the last case, if you mix the back vocals with the rest and they are not too loud, it is possible to achieve good (mix) results.

Cubase’s transpose track does a pretty good job at transposing vocal and everything else up and down 4-5 semitones with almost no artifacts.

I would think, that the same algoritm would do a better job for the harmonies feature than the current.

But maybe it’s not possible since they don’t use that. 🤔