Collabora apps not working

I am trying to make working collabora online.
I install both apps collabora on line and collabora CODE.
I succeed in connecting to CODE through http://localhost:9982. (curl + nextcloud app)
But, when I double click on a doc, a page opens but stay blank page.
I review logs in data/nextcloud.log.
It writes : “Exception”:“OCP\Http\Client\LocalServerException”,“Message”:“Could not detect any host”,“Code”:0,…
I review discussions on bugs, but never find anything.
Is there a known bug ? Any workaround ?
Thank you