Ok i restart from scratch:

this is good:

Using a virtual machine (VM) | Centreon Documentation

this is bad:

Discover the Centreon web interface | Centreon Documentation

the yum update on the fresh vmbox does not work:

Error:
 Problem: package perl-JSON-Path-1.0.3-1.el8.noarch requires perl(Exporter::Tiny), but none of the providers can be installed
  - cannot install both perl-Exporter-Tiny-1.002002-1.el8.noarch and perl-Exporter-Tiny-1.000000-4.el8.noarch
  - cannot install the best update candidate for package perl-JSON-Path-1.0.3-1.el8.noarch
  - cannot install the best update candidate for package perl-Exporter-Tiny-1.000000-4.el8.noarch
(try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)
 

You have to install:
yum install perl-Exporter-Tiny-1.000000-4.el8.

After installation You will be able to update perl-JSON-Path.