Podcast Episodes not being published at full length

Hi guys,

I’m facing an issue: I have an episode file on my server that is an hour long, with no empty space in the ending and a size that reflects that.
I have a podlove plugin that tells me it’s 1 hour long.
I have podcast platforms that all only play the first 20 minutes of the episode.
This is even clear through two links:
004_Lasst_Uns_Aussterben!.st2 – Der Shrinking Thinking Podcast (The Website, with the full length)
Spotify (Spotify, with the first twenty minutes)

Can anyone help please?
Very weird…