If a TXT record is longer than 255 characters, the controller adds a tab separator. The script receives the record with the tab separator and writes it to the DB. So far, so good. However, PowerDNS does not serve the request correctly because it performs string splitting on its own. Instead, it does some weird tab encoding.
To address this issue, the script needs to take corrective action by replacing the tabs with an empty string before storing it in the database.