Python-BluetoothConnection with python3 by using socket: [Errno 112] Host is down

Question

i#m coding an two python-scripts which allow me to chat between two different PCs by using Bluetooth and socket.

On PC-1, at first, i run this command to get the mac address, because i would like to use PC-1 as a server:

ssv@jsz:~$ bluetoothctl 
Agent registered
[CHG] Controller **00:28:F8:A2:B6:2D** Pairable: yes
[bluetooth]# 

On PC-1, i execute this Script (Server):

import socket


server = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, socket.BTPROTO_RFCOMM)
server.bind(("00:28:F8:A2:B6:2D", 4))
server.listen(1)

client, addr = server.accept()

try:
    print("server is listening")
    while True:
        data = client.recv(1024)
        if not data:
            break
        print(f"Message: {data.decode('utf-8')}")
        message = input("Enter message")
        client.send(message.encode("utf-8"))
except OSError as e:
    pass

client.close()
server.close()

This is the terminal output of PC-1's code

ssv@jsz:~$ /bin/python3 /home/ssv/Documents/Praxisphase/sonstiges/Chat_app/server.py
/bin/python3 /home/ssv/Documents/Praxisphase/sonstiges/Chat_app/server.py

After that, on PC-2, i run this code(client):

import socket

client = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, socket.BTPROTO_RFCOMM)
client.connect(("00:28:F8:A2:B6:2D", 4))

try:
    print("searching server")
    while True:
        message = input("type the message: ")
        client.send(message.encode("utf-8"))
        data = client.recv(1024)
        if not data:
            break
        print(f"Message: {data.decode('utf-8')}")
except OSError as e:
    pass

client.close()

This is the terminal outout of PC-2

timo-vincent@timovincent-E15301:~/Dokumente/SSV/Praxisphase/ProjektEmbededSystemConfigurationApp/BluetoothConnectionViaBluez$ sudo python3 client.py
Traceback (most recent call last):
 File "/home/timo-vincent/Dokumente/SSV/Praxisphase/ProjektEmbededSystemConfigurationApp/BluetoothConnectionViaBluez/client.py", line 4, in <module>
    client.connect(("00:28:F8:A2:B6:2D", 4))
OSError: [Errno 112] Host is down

On both PCs, PC-1 and PC-2, bluetooth is activatet. I've got already restart the bluetooth device on both PCs and the PCs itself, too

Does anyoine have a idea, what's is going on?

Thank you!

PS: The codes based on this video https://www.youtube.com/watch?v=8pMaR-WUc6U

I would like to connect two PCs via bluetooth and chat between them