NextCloud and collabora (not docker) don't open documents and gives grey page

Hello, I use centos7 x64 bits machine.
I installed nextcloud 14 on it and it’s working nice
i installed collabora on it from binaries (not docker image), and it seems also to be working fine as i can open admin page and i see the xml tags.

Both nextcloud and collabora are with no ssl as i configured them to use http not https as a test.

The problem is after doing the integration.
When i open any document it doesn’t give error but it gives a Grey window of collabora with no way to do anything

After checking logs specially “loolwsd.log” , I found the following:
“WRN WOPI host did not pass optional access_token_ttl| wsd/FileServer.cpp”
But, I have no clue about the cause or how to solve it.

the url that i get is similar to:

where x.x.x.x is my server real IP.
Please, any suggestions or ideas?

Had a similar issue on Debian and have to install collabora version 5.3 - not 6.x

Thank you for your suggestion.