Hey Frank,
Here's the deal. If even after the host reboot you are unable to connect to the host, there are just two possibilities, the port 443 might be blocked (ssh uses port 22) or the hostd service might be crashing.
Can you try the following command and share the output?
less /var/log/vmware/hostd.log or less /var/log/hostd.log depending on the version or ESX you are running.
Also try a telnet hostname of ESX 443 to check if this is a ports issue.
So if the hostname is localhost
telnet localhost 443
Regards
a
