Dear Fannarino,
First, what version of FOG are you using? I assume you are using this FOG server for DHCP?
with your VM is the networking set to NAT for the VM or Bridged?
First - Did the install script finish without any errors? I would check that as the script handles all the database stuff FOG needs. Check the Docs on installing FOG to ensure you did all the steps on the database.
Since you are using a different network than that one you use for the internet, then you need to ensure all IP addresses for the interface you are using match. If you set these up with a script using a network for the internet and then changed it, then you will need to ensure all IP addresses match.
Second - On your Fog Settings in the Web UI, check your various IP Address settings particularly
Fog Configuration: TFTP Server
Fog Configuration: Web Server
Storage Management > DefaultMember
Next, check in your Fedora VM, check the following.
/etc/dhcp/dhcpd.conf
/tftpboot/default.ipxe
Then check your FOS, which is the bzimage files FOG uses to load the OS your computer is pxebooting. this might effect proper booting or execution of any task in FOG. You can check this in Fog Configuration, then click on the blue button that says "DefaultMember FOG Version: ( ) it will list two files.
bzimage Version
bzimage32 Version
If this is too old you can replace these, which are located in redhat OSes (I use rocky linux myself) under /var/www/html/fog/service/ipxe. You would need to replace about 4 files which you can download from github, under fog project.
These are the points I can think of.