Nextcloud - Collabora GuzzleHttp\Exception error

Error when connecting Nextcloud Office app to Collabora Code server.

Nextcloud 25.0.2 on
Nextcloud Office app 7.0.2
PHP 8.1
Collabora code server (latest) on separate server, behind NGINX reverse proxy, SSL Certificate CA
A record pointing subdomain to Collabora server

Can reach Collabora server externally via, result ‘OK’

Nextcloud error code

GuzzleHttp\Exception\ClientException: Client error: GET resulted in a 404 Not Found response: <meta name=“viewport” content="width=device-width, initial-scale=1, sh (truncated…)


Any thoughts…