Can't go back after network check

[pietrodicaprio]

In my VM the installer lagged and I skipped the step after the keyboard layout selection because I clicked twice on the "next" button and started the network check.
I want to go back to check what I skipped but it's not possible because when I go back from the Time Zone selection I enter the network check and it's denying to go back further.

I'm also wondering why the "Chec Again" button is there (it's deactivated?) if there as not been any networking issue