Blank screen in collabora integration

Hi, I am trying to install nc 14 with collabora office in the same server to test the application. My server is ubuntu 18.04.
As a first step I did an installation without ssl and it was fine, so I believed environment and libraries were ok.
Next I am configuring as per official docs with a new collabora container (not the same I used for previous installation) using apache2 for reverse proxy. I have nextcloud working, but the integration with collabora give me just a blank screen.
I dont want to bother you with logs and configs if is not useful and as first step I am asking if you know some hints to troubleshoot the problem.
I guess problem arise with reverse proxy …
Anybody has a clue?
thank you

container/machine rebootet? what kind of certificates are you using? letsencrypt/selfsigned?

otherwise: will do the job for you. no need for manual installation. (but still you have to reboot. and you need letsencrypt certificates. for selfsigned there is an open issue I couldn’t solve up to now.)

now I am using letsencrypt certificates in 2 dns names, 1 for nextcloud and 1 for collabora. Reboot of the server (so nextcloud and docker parts) had no effect.
I had a fast look at the info you suggested and I noticed that usually reverse proxy is done with nginx, not apache! May be I have to follow this.
thank you

if you are looking for a good howto: