On the cluster gateway, you can run this command to see if it's connected to the management server (or log server, whichever is appropriate for you):
cpstat -f log_connection fw
If the log server is not reporting "Connected", then you may need to do some troubleshooting to learn why.
You can see what logging connections are attempted, by running this "netstat" command:
netstat -anp |grep ':257'
This will tell you what remote IP the gateway is attempting to reach. If you see "ESTABLISHED", then the gateway is connected to a log server of some kind. If you see anything else, then you have some kind of network issue.
Look at the "masters" file to see if there is some error or other issue:
ls -l $FWDIR/conf/masters
lsattr $FWDIR/conf/masters
cat $FWDIR/conf/masters
If you see "----i----------- /etc/fw/conf/masters" in the output of the second command, that means your file is read-only and it cannot be updated each time you do a policy install. You often need this if your management server is hosted behind a NAT gateway, such as a CloudGuard management host.
If the output of the 3rd command looks wrong, then you need to learn why.