After all clients are registered to a deployment server, why are only half of the number of clients detected in forwarder management?

I want to configure dedicated deployment server for 50 clients, my deployment server specification is Oracle Linux, 12GB RAM, 8 CPU Cores. But after all clients are registered to deployment server, only 25 clients detected in Forwarder Management, I try to reload using Splunk reload deploy-server command, for a while 50 clients detected and after that it's back to 25 clients.