Perhaps this is what you’re looking for:
Not sure if your issue is the same, because your description seems to suggest a different manifestation (spinning on network setup). But there’s a hint, which resources are being checked.
Other than that, I can only suggest to pull out the big gun:
sudo apt install wireshark
You can install software in the live session; will be installed to volatile tmpfs storage.
Then sniff out the outbound requests. Or check with your firewall what it rejects/drops. If you need the IP of the live session:
ip address
It’s possible that’s unrelated. You can setup the network connection by other means, restart the installer app, and just proceed with offline mode. The only implications of online mode, I know of:
- restricted drivers and codecs (license prohibits distribution on the ISO) can be downloaded and installed during installation
- install security updates instead of the packages on ISO, where applicable
Autoinstall shouldn’t be effected, I reckon.
Or try setting up the network, restart the installer app, and click the wireless connection, when asked. Since it will already be set up, there should be no obstacle.