Remaining mutation is still seen even when all the ingestion has finished

While trying to ingest data from a remote cluster (cluster version 7.1.0-1058), even after the ingestion has completed, the remaining mutation numbers are still seen on webUI and same can also be seen using the analytics/node/agg/stats/remaining API.

Steps to reproduce -
1. Have a remote cluster with 7.1.0 version.
2. Load travel-sample bucket on remote cluster.
3. Create a link to remote cluster from local analytics cluster (local cluster is in 6.6.3 version).
4. Create a remote dataset using the above link.
5. connect the remote link.

Observation -
1. When we connect the link, the initial mutation count is shown as 83129.
2. Ingestion gets completes.
3. Remaining mutation is still shown as 1103.