Slow Batched Insert and Index Spread Across Nodes Issue

**Describe the problem**

1. A batched insert on a table with two indexes is running pretty slow taking nearly 300ms to complete. The cluster is 5 nodes in a single-region. I've attached diag bundle.
2. In the initial load test, right after creating the indexes (on INT8 fields), we noticed the index was all in one place on one range on a single node. However, now we see that they have spread out across multiple ranges and multiple nodes. Is it normal for indexes to split like this after some time?

**Environment:**
- Dedicated
- Cockroach V22.2.11

Jira issue: CRDB-30102