NHK World audio on demand: some "Friends Around the World" URLs unsupported

[an-nhk-world-fan]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2020.05.08
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar issues including closed ones

Verbose log

D:\>youtube-dl -v https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/listener-20200315-en/
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/listener-20200315-en/']
[debug] Encodings: locale cp1252, fs mbcs, out cp850, pref cp1252
[debug] youtube-dl version 2020.05.08
[debug] Python version 3.4.4 (CPython) - Windows-7-6.1.7601-SP1
[debug] exe versions: ffmpeg 4.0.2, ffprobe N-91666-g70d2bab80b, rtmpdump 2.3
[debug] Proxy map: {}
[generic] listener-20200315-en: Requesting header
WARNING: Falling back on generic information extractor.
[generic] listener-20200315-en: Downloading webpage
[generic] listener-20200315-en: Extracting information
ERROR: Unsupported URL: https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/listener-20200315-en/
Traceback (most recent call last):
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp4z7swg
z7\build\youtube_dl\YoutubeDL.py", line 797, in extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp4z7swg
z7\build\youtube_dl\extractor\common.py", line 530, in extract
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp4z7swg
z7\build\youtube_dl\extractor\generic.py", line 3370, in _real_extract
youtube_dl.utils.UnsupportedError: Unsupported URL: https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/listener-20200315-en/

Description

Some Friends Around the World URLs unsupported, such as https://www3.nhk.or.jp/nhkworld/en/ondemand/audio/listener-20200329-en/

Perhaps this is because of the "-en" at the end of the URL?