Missing existing network

`amsterdam_nl, bergamo_it, berlin_de, bremen_de, dusseldorf_de, espoo_fi, hamburg_de, helsinki_fi, london_gb, munich_de, oulu_fi, stockholm_se, tampere_fi, vantaa_fi, warsaw_pl` all have no existing network. Is this a known limitation or an export bug?

The issue names no files, tests, or entry points. Start by reproducing the missing-network result for the 15 listed cities and compare the exported records with their source network data. Done means determining whether this is a known limitation or an export defect, then documenting the cause or correcting the affected exports.

Written by the indexing model from the issue text.