I could reproduce the issue, I need to check, there were some changes in the nginx config files.
As a workaround you could go back to the previous version 7.1.1:
yum downgrade https://github.com/ONLYOFFICE/DocumentServer/releases/download/v7.1.1/onlyoffice-documentserver.x86_64.rpm
signal-event nethserver-onlyoffice-update