ISSUE DESCRIPTION AND IMPACT
2dsphere indexes on metric data in time series collections are not correctly maintained when inserting data. Index keys may not be generated and inserted into the index, causing geospatial queries optimized by it to return incomplete results.

2dsphere indexes on the metadata value in time series collections are not affected.

DIAGNOSIS AND AFFECTED VERSIONS
Inserting data into MongoDB versions 8.0.0-8.0.15 under FCV 8.0 and 8.2.0-8.2.1 affects 2dsphere indexes on metric data in time series collections. Upgrading to a fixed version prevents further occurrences but does not repair affected indexes.

All 2dsphere indexes on metric data in time series collections with inserts on affected versions should be assumed to be affected. Index inconsistency can be confirmed by running the validate command. However, validate on MongoDB 8.2.0-8.2.3 may result in a false negative where the index inconsistency is not reported.

REMEDIATION AND WORKAROUNDS
Affected indexes can be repaired by dropping the index and recreating it. Alternatively, performing logical initial sync on all nodes in the cluster in a rolling fashion also repairs the index.

Time series collections with configured TTL expiration may choose to let TTL expire affected data over time as the remediation procedure.