GCPStorage sink plugin committed offsets

We are using the GCP Storage Sink Connector with the following property set to false:

“connect.gcpstorage.exactly.once.enable”: “false”

In our test, we send 10 records, which are processed and written to a file. However, when we delete the connector configuration or job and then recreate the job, a new file is written starting from offset 9. Is the plugin reporting the committed offset as the actual offset minus 1?