Web manifest is not accessible after forcing SSL

aurora.igloo.ooo has a strange server and preventing some requests from accessing manifest.json.
First time when I clicked your link, I saw the manifest.json. Then I called the main-page by removing the filepath, clicked back in browser-history to see the manifest again and got this shown (with http-response-code 200):

Looking at it in the network-console it's still getting more confusing but also leads to the source of the error:

It's complaining about missing enabling of javascript, so they make some weird things with javascript and probably some hidden redirect too (else the response code would be 3xx). Perhaps they never want the manifest being accessed from outside and it's not configured properly and can be seen under some conditions.

I don't have a quick solution for your problem but it's quite obvious that some clients can't access the manifest and you've to search for another solution. If you're working for aurora.igloo.ooo you've to speak with the frontend-developers and/or server-admins to change something, else you've to offer your own manifest-file. Also it's possible that they offer a solution for the problem, but for that you've either to have access to some FAQ or knowledge-base or you've to contact the support.