What is the most likely cause of an Objects bucket that is shared with multiple...

According to Nutanix Objects User Guide1, an object store is a logical grouping of buckets that share a common namespace and configuration settings. A bucket is a container for objects that can be accessed by authorized applications and users using S3-compatible APIs.

Objects Storage provides a simple and scalable S3 compatible storage tier on top of your Nutanix AOS platform2. There is no limit on objects per bucket3, but there is a limit on the total capacity of an object store that can be configured during its creation or modified later4.

Therefore, if an object store is shared with multiple users, it is possible that other users have written to the buckets in the object store and consumed its assigned capacity limit.