Accessing application results in 502. "upstream connect error or disconnect/reset before headers. "

Trying to publish an application to the railway platform.
It is a mixture of react, together with some self-built legacy server-side-rendering legacy code.

It has a connection to graphql, which we've allowed through cloudflare already. The same approach worked for other projects.

But as this one is unique in its architecture, we are not able to really put it to work.

It seems to end up in green state, but accessing the webpage just results in upstream connect error or disconnect/reset before headers. reset reason: protocol error

I thought it might be a http/1.1 vs http/2 issue, but accessing the page with curl, using either of protocols doesn't end in different result.

28efb0c1-ffd8-474d-94e0-9671f29845d0
Service id: bd65b2af-60e3-4a2c-8374-13c7e84359b5

please share screenshots and domains so we can troubleshoot ourselves

Sorry. Was end of workday already.

Can you perhaps access from the service id?

If i access my internal healtcheck url, that responds.

I do not work for railway, your project id does nothing for me

I'm not seeing any issues yet?
it's totally okay if you want to pick this thread back up when you're on a computer

I see.
Url is as follows.
https://sports-app-pr-2420.up.railway.app/de/sports
This just returns the protocol error thing.
But should instead render a whole page.

well what do your deployment logs say?

Nothing.
I've debugged it that far that i have 0 error logs remaining.

seems like you need to add some error logging
really hard to debug stuff without logs

Yeah. I tried debugging it whole day. No clue what goes wrong. From logs all seem nice.

Thought of 1 thing.actually. will try it when im near pc again

sounds good
but yeah not much i can help with here without logs