list-available-managed-rule-group-versions API returns not existing CurrentDefaultVersion?!

Waiting for AWS Support to response.. Current state:

Version_1.6_PLUS_RC_COUNT is similar to the Version 1.6 with added new rules in count mode to the default version. Once we test it on our end, we set the default back to the recommended static version ( removing the _RC_COUNT at the end ). As you mentioned, it causes confusion among the default versions. So, I went ahead and provided a feeback to our internal team regarding the issue.