Imagine you have created a correct config, you want to download it -> all is good, it allowes to choose any of the formats. Then I close the popup, spoil my config and again click the Download button -> Now it shows error message that it is an Invalid configuration and doesn't allow to download the config

Now I go back to my config and fix the spoiled part, now it looks good -> Clicking Download button -> It still shows the error message from the last spoiled one and it is not possible to download it.

Then I go back to my config and spoil it again but in other place (not the same) > clicking Download button -> Now the error message is updated with new spoiled issue.

So seems that the downloadable config in Download area is refreshed only if there is an error in the config. If it is fine, it is not refreshed from the previous error which doesn't allow to Download the config.