Not clear why you used an old ISO.....
But with that ISO (and an older kernel), did you have wifi in live mode?
No error messages for iwlwifi, so not clear yet what the issue is. What happens if you restart iwd?
sudo systemctl restart iwd
Post the output of that command, and best to also include the output of
sudo systemctl status iwd.
If restarting iwd does not make any difference, post the output of
sudo dmesg | grep iwlwifi also.