Yeah the timeout error is flaky (your last request happens to have been successful). As mentioned in our original post you can trigger it by retrying with different query parameters until you see a failing one: curl -v https://app-site-association.cdn-apple.com/a/v1/testa.uff2.de\?foo3 If you swap the 3 with different numbers you should see a failing one as well.

Checking with https://testa.uff2.de/.well-known/apple-app-site-association shows that the file also hosted there. Technical Q&A QA1919 mentioned in my last answer explains the /apple-app-site-association request. But still, we can't figure out why the primary request times out.

My response got too long for a direct comment. Please see: https://developer.apple.com/forums/thread/844781?answerId=904472022#904472022