Multiple Foreign Keys to same column and a multi-column index cause foreign key constraints to fail

CREATE TABLE IF NOT EXISTS user (

id INT NOT NULL AUTO_INCREMENT,

name VARCHAR(55),

PRIMARY KEY (`id`)

);

CREATE TABLE IF NOT EXISTS user_map (

map_id INT NOT NULL AUTO_INCREMENT,

user_a INT,

user_b INT,

  PRIMARY KEY (`map_id`),

  UNIQUE KEY `one_way` (`user_a`,`user_b`),

  UNIQUE KEY `other_way` (`user_b`,`user_a`),

  CONSTRAINT `acc_connections_ibfk_1` FOREIGN KEY (`user_a`) REFERENCES `user` (`id`) ON UPDATE CASCADE ON DELETE CASCADE,

  CONSTRAINT `acc_connections_ibfk_2` FOREIGN KEY (`user_b`) REFERENCES `user` (`id`) ON UPDATE CASCADE ON DELETE CASCADE

);

INSERT INTO user (name) VALUES ("User A");

INSERT INTO user_map (user_a,user_b) VALUES (1,1);

UPDATE user set id = 10 where id = 1;