RDS Postgres Autoscaling and Storage Issue

Currently, I'm managing an RDS Postgres database instance of type db.m5.8xlarge, operating on Engine version 10.18. The source database instance size is 65,536 GiB, with both allocated storage and maximum storage threshold set at 65,536 GB. Remarkably, storage autoscaling is enabled for this instance. (The allocated storage was at 65,536 before encountering the situation mentioned below )

In recent weeks, we confronted a situation involving a worm that led to the duplication of transaction logs, causing the database's storage capacity to reach its maximum limit. After addressing this issue and purging the duplicated logs, the occupied storage has been notably reduced by several terabytes. Presently, the database instance occupies around 6-7 terabytes.

Curiously, the autoscaling mechanism has yet to come into effect, and the instance still reflects a provisioned storage of 65.3 TB.

Upon inspecting the configuration tab, I observed that the storage autoscaling is marked as "Disabled," despite the instance being configured for autoscaling. Furthermore, recent event logs contain the message: "Storage size 65536 GB is approaching the maximum storage threshold 65536 GB. Increase the maximum storage threshold."

Interestingly, under the monitoring section, the reported free storage space has increased to 67.4 TB.

I'm somewhat puzzled by this scenario, as I anticipated the autoscaling feature to adjust the storage in line with actual usage. I would highly appreciate any guidance, insights, or troubleshooting advice from the community to help address this issue and enhance my understanding of the autoscaling behavior.