Vncserver service is dead immediately after starting vncserver@:x service

Issue

• Vncserver service is dead immediately after starting vncserver@:x service

  #systemctl status vncserver@:<port>
  ● vncserver@:<port>.service - Remote desktop service (VNC)
     Loaded: loaded (/usr/lib/systemd/system/vncserver@.service; disabled; vendor preset: disabled)
     Active: active (running) since Sun 2020-11-29 22:36:11 EST; 20ms ago
    Process: 85358 ExecStart=/usr/libexec/vncsession-start :1 (code=exited, status=0/SUCCESS)
   Main PID: 85364 (vncsession)
      Tasks: 1 (limit: 819801)
     Memory: 2.5M
     CGroup: /system.slice/system-vncserver.slice/vncserver@:1.service
             ‣ 85364 /usr/sbin/vncsession root :<port>
  
  #sleep 2;systemctl status vncserver@:<port>
  ● vncserver@:<port>.service - Remote desktop service (VNC)
     Loaded: loaded (/usr/lib/systemd/system/vncserver@.service; disabled; vendor preset: disabled)
     Active: inactive (dead)