Feed no longer found / episodes not shown

Hi, after more than a year with almost no problems with Podlove Publisher my automated publishing process which hackily uses Selenium for the episode assets (could maybe by now be replaced with the API) threw an error. When checking in the WP-Admin panel I saw that the Podlove plugin had been updated to 4.0.9 (this is not done by me). I, then, manually updated the existing episode drafts and published them but they did not appear in the podcast feed.
I saw that the suffix of the feed URLs of the podcast feeds has changed, i.e. the wpmfeedkey number from 3 to 707 and the hex string, too, like in: https://domain/feed/feedslug/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303 They are all protected with “WordPress User database”. Adding these new feed URLs to the Podcast Addict app shows the podcast title but does not show any episodes; Apple Podcasts does not even show the title: “Unable to Follow. Podcast cannot be added because the server or feed cannot be found.” To test, I also created a new unprotected podcast feed with a new corresponding episode asset type which has the same issues.
All episodes (old and new ones) appear under the Dashboard. The media files are correctly verified.
I thought that the issues might be due to the new version and downgraded the plugin to 3.8.12 to no avail. After the downgrade there was a WP mail highlighting an error with https://domain/wp-admin/admin.php?page=podlove_Support_settings_handle

WordPress-Version 6.3.2
Aktives Theme: eleven40 Pro (Version 2.2.3)
Aktuelles Plugin: Podlove Podcast Publisher (Version 3.8.12)
PHP-Version 8.2.13

Ein Fehler vom Typ E_ERROR wurde in der Zeile 265 der Datei /nas/content/live/username/wp-content/plugins/podlove-podcasting-plugin-for-wordpress/lib/modules/logging/logging.php verursacht. Fehlermeldung: Uncaught Error: Class "Spyc" not found in /nas/content/live/username/wp-content/plugins/podlove-podcasting-plugin-for-wordpress/lib/modules/logging/logging.php:265
Stack trace:
#0 /nas/content/live/username/wp-includes/class-wp-hook.php(310): Podlove\Modules\Logging\Logging->dashoard_template('')
#1 /nas/content/live/username/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters('', Array)
#2 /nas/content/live/username/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#3 /nas/content/live/username/wp-content/plugins/podlove-podcasting-plugin-for-wordpress/lib/settings/support.php(79): do_action('podlove_support...')
#4 /nas/content/live/username/wp-includes/class-wp-hook.php(310): Podlove\Settings\Support->page('')
#5 /nas/content/live/username/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters('', Array)
#6 /nas/content/live/username/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#7 /nas/content/live/username/wp-admin/admin.php(259): do_action('podlove_page_po...')
#8 {main}

Maybe someone can help. I assume the old URLs could be redirected to the new ones, although, I do not know why the URLs changed in the first place. Alas, the new URLs currently do not work at all. The system report is below. Thank you! (Ich spreche auch Deutsch :slight_smile:

Website                    https://domain
PHP Version                8.2.13
WordPress Version          6.3.2
WordPress Theme            eleven40 Pro v2.2.3
Active Plugins             
           - Polylang v3.5.3
           - TablePress v2.2.4
           - Application Passwords v0.1.3
           - Bulk Post Update Date v1.5.0
           - Category Sticky Post v2.10.1
           - Easy Custom Auto Excerpt v2.4.12
           - ICS Calendar v10.13.1.1
           - Import Users from CSV v1.1
           - Make Connector v1.5.8
           - Loco Translate v2.6.6
           - MailOptin - Lite v1.2.65.1
           - Podlove Podcast Publisher v3.8.12
           - Podlove Web Player v5.7.3
           - Post Snippets (free) v4.0.4
           - Print, PDF & Email by PrintFriendly v5.5.2
           - Redirection v5.4.1
           - S3 Media Maestro v4.1.9
           - Search & Replace v3.2.1
           - Shortcodes Ultimate v7.0.1
           - SMNTCS Custom Logo Link v2.2
           - SVG Support v2.5.5
           - Thrive Apprentice v5.13
           - Thrive Clever Widgets v2.9.1
           - Thrive Leads v3.26
           - Thrive Ovation v3.26
           - Thrive Product Manager v1.18
           - Thrive Quiz Builder v3.26
           - Thrive Ultimatum v3.26
           - Thrive Architect v3.28
           - Ultimate Category Excluder v1.7
           - Benutzer-Menüs v1.3.2
           - Widget Context v1.3.2
           - WishList Member™ Legacy v3.24.5
           - WP All Import v3.7.3
           - WP Courseware v4.10.4
           - Kategorien zu Tags Konverter Importer v0.6.1
           - Zotpress v7.3.7
WordPress Database Charset utf8
WordPress Database Collate utf8_unicode_ci
Publisher Version          3.8.12
Publisher Database Version 153
Web Player Version         player_v5
Monolog Version            1
open_basedir               ok
curl Version               7.88.1
iconv                      available
simplexml                  ok
max_execution_time         3600
upload_max_filesize        50M
memory_limit               512M
disable_functions          apache_child_terminate,apache_get_modules,apache_get_version,apache_getenv,apache_note,apache_setenv,disk_free_space,disk_total_space,diskfreespace,dl,exec,fastcgi_finish_request,link,opcache_compile_file,opcache_get_configuration,opcache_invalidate,opcache_is_script_cached,opcache_reset,passthru,pclose,pcntl_exec,popen,posix_getpid,posix_getppid,posix_getpwuid,posix_kill,posix_mkfifo,posix_setegid,posix_seteuid,posix_setgid,posix_setpgid,posix_setsid,posix_setuid,posix_uname,proc_close,proc_get_status,proc_nice,proc_open,proc_terminate,realpath_cache_get,shell_exec,show_source,symlink,system
permalinks                 ok (/%postname%/)
podlove_permalinks         ok
podcast_settings           ok
web_player                 ok
podlove_cache              on
  - mp3    audio/mp3        https://domain/feed/feedslug1/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303
  - mp3    audio/mp3        https://domain/feed/feedslug2/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303
  - m4a    audio/mp4        no feed
  - mp3    audio/mp3        https://domain/feed/feedslug3/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303
  - mp3    audio/mp3        https://domain/feed/feedslug4/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303
  - mp3    audio/mp3        https://domain/feed/feedslug5/?wpmfeedkey=707;8c9bdc2aee7e8c42b8fe04f81dd6a303
cron                       ok
duplicate_guids            ok

0 errors
0 notices
Nice, Everything looks fine!

What is wpmfeedkey? This parameter does not come from the Publisher.

The error you can fix by disabling the Logging module under Modules (or upgrading to Publisher v4 again)

wpmfeedkey comes from the WishList Member plugin but I do not think it is the culprit as the same problem occurs on the mirror/test site when the WishList plugin is uninstalled and the feed URLs do not have any suffix after feed/feedslug, plus, the WishList settings have not been changed (the wpmfeedkey change surprises me, though, but was probably due to an update of that plugin).

From the Podlove interface everything seems okay, the API works, too, and gets the episodes etc. but the feeds are not found (Apple) or do not have any episodes (Podcast Addict).