Impossible to upgrade since 2.1.5

Support
1

Hi, I have two syncthing instances - which have been working for years - on two different servers, which I tried to classically update, from 2.1.3 to 2.1.5 or 2.1.6. I was unable to access them.

  • systemctl status syncthing@syncthing doesn’t give me anything wrong,
  • they are behind caddy (2.11.4) with the usual
    reverse_proxy http://localhost:8384 {
      header_up Host {upstream_hostport}
    }
  }
  • downgrading them to 2.1.3 is fine!

Any idea, any help would be welcome! Thanks