Auphonic not displaying Sources

Hello Community!

Unfortunately Auphonic integration is not working poperly.
I Connected Podlove with Auphonic and added Google Drive and Dropbox as services in Auphonic. But Podlove Publisher is only “Updating Sources…”. No Sources are selectable.

The Connection Podlove -> Auphonicseems to be OK, because existing Productions are available. Also the Connection Auphonic -> Google Drive works fine.

I also used the Clear Cache and Repair Buttons in Tools and disconnected (and reconnected) Auphonic with Podlove. Am I doing something wrong?

PHP Version                7.0.32-nmm1
WordPress Version          5.1
WordPress Theme            Pravda - Retina Responsive WordPress Theme - Child v1.04
Active Plugins             
           - Redux Framework v3.6.15
           - Ivory Search v4.2.1
           - AJAX Thumbnail Rebuild v1.13
           - Avatar Privacy v2.0.5
           - Better Recent Comments v1.0.6
           - Borlabs Cookie - Cookie Opt-in v1.9.7
           - Disable Emojis (GDPR friendly) v1.7.2
           - HTTP-Header zur Verbesserung der Webseiten-Sicherheit v2.5
           - WPBakery Visual Composer v5.1.1
           - Lightweight Social Icons v1.0.1
           - Limit Login Attempts Reloaded v2.7.3
           - Loco Translate v2.2.1
           - Maintenance Page v1.0.8
           - Meta Box v4.16.3
           - NinjaFirewall (WP Edition) v3.8.2
           - PB SEO Friendly Images v3.1.0
           - Podlove Podcast Publisher v2.7.22
           - Publish Confirm v1.0.2
           - Really Simple SSL v3.1.5
           - Remove Comment IPs v1.0.2
           - Remove Google Fonts References v2.6
           - Shariff Wrapper v4.6.1
           - Shortcodes Ultimate v5.3.0
           - TinyMCE Advanced v5.1.0
           - TinyMCE Clear Float v1.3.2
           - TinyMCE Vorlagen v4.8.1
           - UpdraftPlus - Backup/Restore v1.16.6
           - Yoast SEO v9.7
           - WP DSGVO v2.1.1
           - WP-Piwik v1.0.19
           - WP Review v5.2.0
WordPress Database Charset utf8
WordPress Database Collate 
Publisher Version          2.7.22
Web Player Version         podigee
Twig Version               1.36.0
open_basedir               ok
curl Version               7.47.0
iconv                      available
simplexml                  ok
max_execution_time         30
upload_max_filesize        200M
memory_limit               256M
permalinks                 ok (/%postname%/)
podlove_permalinks         ok
podcast_settings           ok
web_player                 ok
podlove_cache              on
  - mp3    audio/mpeg
cron                       ok

0 errors
0 notices
Nice, Everything looks fine!