replication-manager strict mode not detected but no such parameter available.

[bmillemathias]

I got a message from replication-manager OPENED WARN0070 : No GTID strict mode on master bmm-1:3306 , but such variable does not exist in my version (mysql 5.7.34

(root@localhost) [(none)]> show variables like '%gtid%';
+----------------------------------+-----------+        
| Variable_name                    | Value     |        
+----------------------------------+-----------+        
| binlog_gtid_simple_recovery      | ON        |        
| enforce_gtid_consistency         | ON        |        
| gtid_executed_compression_period | 1000      |        
| gtid_mode                        | ON        |        
| gtid_next                        | AUTOMATIC |        
| gtid_owned                       |           |        
| gtid_purged                      |           |        
| session_track_gtids              | OFF       |        
+----------------------------------+-----------+        
8 rows in set (0.01 sec)                                

the message to be useful should explain based on which parameters it does deduct such information.