Unable to update Neptune cluster to engine version 1.1.0.0

I am trying to update my Neptune cluster from engine version 1.0.5.1.R2 to the latest 1.1.0.0 version, but am unable to do that either via the console (only 1.0.5.1.R2 is in drop down), or using the AWS CLI as suggested in the release notes.

The CLI command I am using is like follows:

aws neptune modify-db-cluster \
    --db-cluster-identifier my-neptune-cluster \
    --engine neptune \
    --engine-version 1.1.0.0 \
    --allow-major-version-upgrade \
    --apply-immediately \
    --db-cluster-parameter-group-name my-neptune-pg \
    --db-instance-parameter-group-name my-neptune-pg

This fails with the error:

An error occurred (InvalidParameterCombination) when calling the ModifyDBCluster operation: Cannot upgrade neptune from 1.0.5.1 to 1.1.0.0

Here are the parameters that are set on both the cluster and database:

$ aws neptune describe-db-cluster-parameters --db-cluster-parameter-group-name my-neptune-pg | jq -r '.Parameters[] | [.ParameterName, .ParameterValue] | @csv'
"neptune_autoscaling_config",""
"neptune_enable_audit_log","0"
"neptune_enforce_ssl","0"
"neptune_lab_mode",
"neptune_lookup_cache","1"
"neptune_ml_endpoint",
"neptune_ml_iam_role",
"neptune_query_timeout","120000"
"neptune_streams","0"

$ aws neptune describe-db-parameters --db-parameter-group-name my-neptune-pg | jq -r '.Parameters[] | [.ParameterName, .ParameterValue] | @csv'
"neptune_query_timeout","120000"
"neptune_result_cache","0"