This article describes the feature of copying the rule from a policy and paste in another or the same policy

The new copied rule appends copy_1 to the name.

This is the expected behavior to avoid duplicate names in the same policy.

If we paste the rule to another policy and if the copied rule name does not exist then it will create a new rule with the same name, if the rule with the same name exists, then _copy_1 will be added.