Chapters don't show up in Podlove Web Player 5

I’m using Podlove for a few years now with .mp3 and .psc files. This worked perfectly so far.
Last week I’ve released a new episode but couldn’t get the chapters to show up in the web player.
Since then the chapters in ALL episodes disappeared.

For example https://www.acsngroup.eu/smart-grid-fh-hagenberg/

Details:

  • I’m using Podlove Podcast Publisher 3.6.1 and Podlove Web Player 5.4.14
  • using Web Player 5
  • testing this problem with Web Player 4 the chapters are missing as well
  • deleted Podlove cache, hit “Repair” button, WP Cron Diagnostics are OK - problem persists
  • no cache plugin involved (like W3 Total Cache)
  • status of episode’s .mp3 file and .psc file are both OK
  • Podlove >> Help only lists old errors and warnings

What could be the problem?

Yesterday I had to disable “SSL peer check” because the episode images didn’t show up in the web player. Could it be an SSL cerificate problem?

I’m still not able to get the chapter tab (provided in .psc files) showing up in the Podlove Player.

My conclusion after a long debugging session:

  • server log files don’t show any warning or error
  • Chrome’s dev console doesn’t give any clue about missing chapter information
  • inspecting the source code is a little tough due the many libs I’m not familiar with

How can I tackle this problem? Are there any logs left which may reveal more debug info?