@clay005:
My suspicion is, It is restarting when someone remote our the server using its the Domain name (or computer name not ip address). Because before i register the IP address to have a name we are using ip address to remote the server and im not having this kind of issue.
This can't be a suspicion, except if you refuse to check your firewall, the rules present on WAN.
There should be none **, and in that case : impossible, non one can connect to your pfSense.
Btw : you just showed that you missed one of the biggest concepts of the Internet : people rarely use IP's, or, they work well. Humans like addresses like test-domaine.fr, which are translated directly to :
test-domaine.fr has address 5.196.43.182
test-domaine.fr has IPv6 address 2001:41d0:2:927b::15
Remember that addresses or URL like test-domaine.fr aren't use on the Internet : you see them on your screen, they are looked up to IP addresses and that it.
The fact that you use a domaine name - like my test-domaine.fr - doesn't mean that people can find you more easily, or not. True is, domaine name are public. But you don't care, you have a firewall, and nothing initialed from the outside come in. That was the very reason you put the firewall in place.
** if there are rules ….. well, you shouldn't. One never does before all consequences are understood ;)
Btw : Never ever expose the pfSense GUI to the outside (WAN or Internet).