Bubbly effect on vocals

Hi

I don't know whether anyone else has experienced this but when I turn on flex pitch and use the

Correction feature It corrupts some of the notes with a kind of "bubbly" sound the best I can describe this and no matter

What I try this note will not improve unless I switch off the flex pitch...

This isn't present whenever I watch any tutorials on flex pitch ...

Can anyone help ??

Also if it was possible to just choose which notes to correct to perfect pitch and not all of them...??

Maybe we could correct that one note by re singing it ......I don't know.??

.....I am waiting for answers...

Thank you