Fails to connect to server (SSL handshake failure)

[OmegaSupreme3]

After update to 0.18.11 the app cannot connect to my server anymore, the reverse proxy reports a SSL handshake failure. Before the update I've never experienced any problems with the app. The setup has been working for almost a year without problems.

• I use a Google ChromeCast 4K (up-to-date)
  
• WiFi connection is working (can browse videos etc.)
  
• The reverse proxy is configured to use a non self-signed SSL certificate (TransIP). The certificate is valid
  
• The reverse proxy also is used for other services and none of those services experience problems
  
• No configuration changes have been made to the reverse proxy
  
• No configuration changes have been made to JellyFin server
  
• JellyFin through the webbrowser, MediaPlayer and the regular Android app work without problems. Both from inside and outside the network
  

What did I try?

• I tried connecting directly to the JellyFin server HTTPS (8095), but no connection could be made
  
• I also tried through HTTP (8096), but no connection could be made
  
• Remove server settings from the app. Did not resolve the issue
  
• Remove the cache/data for the Android TV app. Did not resolve the issue
  
• Reinstalled the Android TV app. Did not resolve the issue
  
• Tried with a different Google ChromeCast 4K. Same issues occur
  
• Checked the logs of JellyFin and couldn't find any relevant information. It seems the app doesn't connect to JellyFin server. The logs do not show any information
  
• Checked the operating system logs, also no relevant information is shown
  
• 'netstat' doesn't reveal any pending connections as well
  

The latter seems to indicate that it might be more of a general connection issue, not only related to SSL connections.

What steps can I take to start resolving this issue? Are there any debug logs for the app?