I even checked the addresses of solo4.ckpool.org and solo6.ckpool.org for the pool.
In all cases, the pool is dead.
I am from Iran.
Could it be because of sanctions?
However, I have no problem with other pools and the device works well.
This could be anything, Your ISP blocks the connection to the pool, the pool's server blocks access from your IP, the ISP of the server blocks access from your country, hard to tell, one thing you could try is to change the DNS on either your miner or the miner itself from the network settings, try 8.8.8.8 or 1.1.1.1, this is the only "cheap and easy" shot I can recommend, the other solutions would be running a proxy or router with VPS capabilities, these options are neither cheap nor easy.