Steps to reproduce:

1. Create a new template 'RabbitMQ duplicate key test'
2. Add 'RabbitMQ cluster by Zabbix Agent' and 'RabbitMQ node by Zabbix Agent' templates
3. Assign 'RabbitMQ duplicate key test' template to a host
4. Go to Configuration > Templates > Select 'RabbitMQ duplicate key test' then go to Discovery Rules
5. Error can be triggered by trying to enable or disable either of the 'Health Check 3.8.10+ discovery' Discovery Rules

The error I think is due to the same key rabbitmq.healthcheck.v3810.discovery being used for uuids 406836367f45425fbd181a20dc3d08d7 and 3c0021a3e57142eb806deb5b47b6700a.

Result:
See attached screenshot...
Expected:

Either the duplicate key is fixed, or perhaps the unique uuid field should be used to check for duplicates instead of the string of the key? We are currently working this issue by having renamed one of the keys to 'rabbitmq.clusterhealthcheck.v3810.discovery'

Please let me know if there is anything else you need from me.

Many thanks and kind regards,

Alex Eastwood