NetBox issue netbox-community/netbox#16640 can corrupt data, this script helps repair data in the specified module, type, and custom field.
Example usage, in our case to evaluate a field called 'references' on all NetBox IPAM Prefixes: python3 netbox_fix_json.py --apitoken=[redacted] --url=https://[your netbox instance] --fieldname=references --module=ipam --type=prefixes --field-name=references
The script is read-only by default. Add --verbose to see the specific objects that are being updated or proposed to be updated. Add --make-changes to affect the data changes after reviewing the output.
It may be a good idea to take a database backup before having this script make changes.