Adapt the operational points schema:

OperationalPointPart {
    local_track_name:   "V1"
    ...
}

1. Perform a migration.
2. Update the schema.
3. Update the Python side (schema + generator).

Notes:
To fix the bug, you must first run the migration, then correct the issue based on the data import.
During the migration, instead of leaving the field empty, you should reuse the value from the track.