Mysql: Incorrect / missing foreign key for innodb tables #1028

Steps to reproduce this issue

Create table:

CREATE TABLE contract_info_lv_tmp111 (
ID int(11) unsigned NOT NULL auto_increment,
Agent_id int(11) unsigned default NULL,
PRIMARY KEY (ID),
CONSTRAINT FK_contract_info_lv_agent_info_lv_zz
FOREIGN KEY (Agent_id) REFERENCES agent_info (ID) ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=25447 DEFAULT CHARSET=latin1

Current behavior

Foreign key tab is empty. There is 'FK_contract_info_lv_agent_info_lv_zz' KEY/BTREE index in 'Indexes' tab.

Tab 'Create code' shows:

CREATE TABLE contract_info_lv_tmp111 (
ID INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
Agent_id INT(11) UNSIGNED NULL DEFAULT NULL,
PRIMARY KEY (ID) USING BTREE,
INDEX FK_contract_info_lv_agent_info_lv_zz (Agent_id) USING BTREE
)
COLLATE='latin1_swedish_ci'
ENGINE=InnoDB
AUTO_INCREMENT=25447;

Executing SHOW CREATE TABLE contract_info_lv_tmp111; returns:

CREATE TABLE contract_info_lv_tmp111 (
ID int(11) unsigned NOT NULL auto_increment,
Agent_id int(11) unsigned default NULL,
PRIMARY KEY (ID),
KEY FK_contract_info_lv_agent_info_lv_zz (Agent_id),
CONSTRAINT FK_contract_info_lv_agent_info_lv_zz FOREIGN KEY (Agent_id) REFERENCES agent_info (ID) ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=25447 DEFAULT CHARSET=latin1

Expected behavior

Foreign keys should remain in 'foreign keys' tab...

Environment

• HeidiSQL version:
  Revision 5978 (yours: 5978)
  Compiled: 2020-05-10 (yours: 2020-05-11)

• Database system and version:
  mysql
  5.6.30-1 (debian) -- not affected.
  5.7.12-5 Percona server -- affected
  5.0.67 - redhat -- affected
• Operating system:
  Win 10 pro 64 bit.