Azure Cosmos DB for MongoDB: Enabling runtime collation on find/aggregate

Problem description

I am trying to enable runtime collation (find/aggregate) on my Azure Cosmos DB for MongoDB clusters in East US to match the behavior of an existing cluster. Currently, some newer clusters reject collation-based queries with error code 115 (CommandNotSupported), while an older cluster accepts similar queries. I want to understand if runtime collation support can be enabled on these clusters, or if there is a way to align their configurations.

Environment

Azure Cosmos DB for MongoDB (vCore), three clusters in East US, application using .NET Core with SDK v10.

What I've already tried

I compared behavior across clusters with the same application workload. The working cluster accepts collation in find and aggregate commands, while the newer clusters return errors. I reviewed the application logs and the commands sent, including the collation document. I also verified the MongoDB compatibility version for all clusters, which is 8.0. All clusters report the same version. I tested the same find and aggregate commands with the collation option removed; the failing clusters succeed without collation, indicating the issue is tied to collation support.

Current status

Currently, the two newer clusters in East US are still rejecting collation in find and aggregate commands with error code 115, while the older cluster accepts these commands. I am seeking guidance on whether runtime collation support can be enabled on the failing clusters, or if there are configuration steps to align their behavior with the working cluster.