Sounds like you’re on the right track. There’s a wire in the trough area that the ball will sit on to close down the leaf switch below. This registers that the ball has drained. Sounds like you just need to adjust either the switch or the wire so that the ball registers.
It should look like this.
B5CBDB7A-EA54-4A54-B729-F95A57D69165 (resized).jpeg