Admin sidebar items overlapping in admin panel

This is a known issue.

The current fix (which may also make it into core) looks like this:

add_action( 'admin_enqueue_scripts', 'chrome_fix' );

function chrome_fix() {

    if ( strpos( $_SERVER[ 'HTTP_USER_AGENT' ], 'Chrome' ) !== false ) {
        wp_add_inline_style( 'wp-admin', '#adminmenu { transform: translateZ(0) }' );
    }
}