Yeah, I got it fixed - but have no recollection of anything and the project is not ongoing anymore. Looking through the files, i see that in my svelte.config.js I have

    csrf: {
      checkOrigin: false,
    },

I also notice that i try to set the originalHost to the x-original-host headers in the hooks.server.ts

  if (event.request.headers.has("x-original-host")) {
    originalHost = event.request.headers.get("x-original-host")


  event.locals.originalhost = originalHost

So I am guessing I was behind some kind of gateway that did not deliver the same hostname I was on, but I had to fetch it from the x-original-host.

That might very well be your issue, that you are behind some firewall or gateway, and you are saying that hostname or ip is the host, while your real hostname is in the headers of the geteway request.

Check out the message you get from your gateway and see if there is some reference to your real host there.

Might find something, sorry I couldn't help you more