I’m really glad to see you are here at the forums and hope you can enjoy your time here and at the game as well!
I’m sorry that you’re having issues with the game launch, usually this error is corrected with the steps you mention you completed already, so in order to review your concern I can recommend you to reach us via chat using the following link: Contact Us | Amazon Games to create a support ticket and review your case deeply.
Please make sure to have the DxDiag ready once you reach support, you can pull it following this steps:
Go to Windows Start search bar and type dxdiag.
Click on dxdiag.exe.
When green progress bar goes away, select Save All Information and save the file to their desktop.
If you need further assistance in any other issue please don’t hesitate in reaching us again!
Every time this error shows up (maybe once a month or so) I flush my dns to fix it:
opening command prompt (start menu → type cmd → hit enter) → type the following:
All this does is flush your dns, if you don’t understand what that means, look it up
If you do not want to trust this, look up how to flush your dns yourself, this is the only fix I have found for this problem, good luck friends