I've downloaded and installed Server 2019 Standard edition with the Desktop Experience, from the Microsoft site, via the link provided here in this forum (the link provided in the post [DISCUSSION] Windows Server 2019 (Build 17763)) and it had the same corrupt behavior, as you report. I'm confused by the idea of an .ISO file downloaded from this forum, versus one downloaded from Microsoft, because the only download links that I find, on this forum, are ones which link to the downloads from the Microsoft site.
I'm sorry to hear that you joined the ranks of Server 2019 OS Corruption... Hopefully you can still use Server 2016. I updated my post with your correction... thanks!