Server stopped responding to hostname and only responds to FQDN

We have a Win Server 2003 VM that serves as our LDAP/DNS server and it's also hosting a web platform on IIS. Usually we access the webplatform by https://hostname/platform but for some reason this just stopped working today and I can't figure out why.

The platform is still accessible by https://hostname.suffix/platform, and equally the hostname does not ping but FQDN does.

This is the ipconfig /all output of the server:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : server00
   Primary Dns Suffix  . . . . . . . : company.local
   Node Type . . . . . . . . . . . . : Unknown
   IP Routing Enabled. . . . . . . . : Yes
   WINS Proxy Enabled. . . . . . . . : Yes
   DNS Suffix Search List. . . . . . : company.local

PPP adapter RAS Server (Dial In) Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
   Physical Address. . . . . . . . . : 00-53-45-00-00-00
   DHCP Enabled. . . . . . . . . . . : No
   IP Address. . . . . . . . . . . . : 192.168.1.126
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . :
   NetBIOS over Tcpip. . . . . . . . : Disabled

Ethernet adapter Local Area Connection 5:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft Virtual Machine Bus Network Ada
pter #3
   Physical Address. . . . . . . . . : 00-15-5D-02-D0-12
   DHCP Enabled. . . . . . . . . . . : No
   IP Address. . . . . . . . . . . . : 192.168.1.50
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.50
                                       192.168.1.1

Ethernet adapter Local Area Connection 6:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft Virtual Machine Bus Network Ada
pter #4
   Physical Address. . . . . . . . . : 00-15-5D-02-D0-11
   DHCP Enabled. . . . . . . . . . . : No
   IP Address. . . . . . . . . . . . : 192.168.1.51
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.50
                                       192.168.1.1

Does anyone have any idea what could be happening?

Thanks in advanced.