This is now possible: in your Live Chess settings under "Board" there is "Move Method" - change it from "Drag Pieces" to "Click Squares"
But it still says that you can use both methods in the '?' tool tip. so if you accidentally klick on a square after highlighting a piece it will move.
If that's the case, it sounds like a bug - report it via https://support.chess.com/article/346-contact-us
It's not a bug if it is said in the tip.
Same problem here, completely threw away a match because of the click to move function. The move method option doesn't even do anything in the settings.