Ableton Forum

Waves' Vocal Bender is my current favorite. There are pitch and formant controls that let you dial in a more natural sound, though it's still not perfect and I have to actively filter pitch adjustment artifacts. I like it though.

https://www.waves.com/plugins/vocal-bender

This is happening to me too. With Ableton 11, I was able to right-click the track panning (in arrangement view) to show an option saying "Select Stereo Pan Mode." Once it switched and gave me control of both R+L channels, the problem stopped happening.