Nextcloud cannot connect to High performance backend.

Hello,
I am facing an issue configuring the high-performance backend (HPB) with Nextcloud Talk.
• After curling /api/v1/welcome, I get a 200 status, signaling the service is active.
• But entering the shared secret and URL in Nextcloud Talk causes a 400 error or “cannot connect to server” message.
• Connection tests between Nextcloud and HPB were successful.
• No logs are generated past “listening on IP:8080” by the signaling.service.

I’d appreciate any troubleshooting suggestions
edit:
Just checked nextcloud log it just gives out "unable to connect (uknown error)

is your signalling server publicly certified, you’ll need an SSL certificate for signalling server.

see High Performance Backend for Talk on Nextcloud with Docker and be sure your secretpasswordkey has min. 24 chars.

O tried with ssl but then switched to http to save time when troubleshooting with the same result