Can you confirm, the issue is summarized as thus:
1: NO network cable connected, installation is successful
2: Network cable connected and internet is available, installation is successful
3: Network cable connected, network is available, INTERNET is unavailable (airgapped lab), installation fails
I believe from what you described elsewhere #3 is the case you are seeing, because you are in a lab with no external access, is that correct?
Can you confirm, the issue is summarized as thus:
1: NO network cable connected, installation is successful
2: Network cable connected and internet is available, installation is successful
3: Network cable connected, network is available, INTERNET is unavailable (airgapped lab), installation fails
I believe from what you described elsewhere #3 is the case you are seeing, because you are in a lab with no external access, is that correct?