I use octoprint on a PC, but cannot connect form the other PC

So I use one of my laptop as octoprint, I followed every step in the tutorial, i can locally access octoprint, but I cannot connect from the other computer on the same network. my network is a mesh WIFI setup that connect directly into the router.

I change the IP address from dynamic to static, and i scan all the network device in my local network, and nothing was found

So is your laptop running a local instance of IPTABLES or UFW - wouldn't be unheard of - you don't say what O/S your laptop is running, open a command window on the laptop running Octoprint and type sudo netstat -tulnp -

You SHOULD see two instances in the local address column showing :::80 and :::443. AND a tcp on 127.0.0.1:5000 which has a python2 program name. HAPROXY listens on IPV4 and IPV6 on port 80 and port 443 and forwards to the localhost listener ONLY on 127.0.0.1. If you take a look in /etc/haproxy.cfg its all listed out.

I'm not expert enough in the configuration of Octoprint to know whether you should open port 5000 to anything other than localhost, but your listeners on port 80 and 443 should be active and port 5000 on localhost.

Then check your security / local firewall configuration - try stopping the services which you can list with sudo service --status-all, on Raspbian and Debian/Ubuntu systems that works. YMMV if you are running a different linux desktop O/S. Static/ dynamic shouldn't matter - if you know the IP address of your laptop the connection should work, but something else is stopping it, hence my suggestion of a local instance of IPTABLES / ufw or something - you will see ufw in the services list..

How are you connecting?
Via hostname or ip?
Try the ip if you didn't before.

One problem is that your WiFi mesh and the router that supports it doesn't do DHCP and dynamic name resolution properly, if you want name resolution on your local network you need more control over names and IP addresses and DNS. You should also look in the arp table on your laptop - sudo arp -a for the IP addresses of other devices, especially when you ping them by IP address. If you want to use names with out fixing DNS/DHCP then you need a local hosts table. On windoze c:\windows\system32\drivers\etc, on Unix, /etc/hosts One line per host / IP. Often on Unix you will only find an entry for 127.0.0.1 localhost. On a Unix dhcp client sudo dhclient -v will show your IP address and the conversation between your device and your DHCP server.