Apple-App-Site-Association (AASA) return 404 Not Found in some CDN nodes.

Hi

We locate the file apple-app-site-association on both https://ourdomain.com/apple-app-site-association and https://ourdomain.com/.well-known/apple-app-site-association

By visit this two urls, we are able to get file content through browser.

We are able to get the file content through https://app-site-association.cdn-apple.com/a/v1/ourdomain.com with US based IPs, Europe based IPs. However, if we visit this url with Asia based IPs, we always got 404 with content Not Found.

Some work CDN nodes:

< Via: http/1.1 ussjc2-vp-vst-009.ts.apple.com (acdn/14319.5), http/1.1 ussjc2-vp-vfe-002.ts.apple.com (acdn/14319.5), https/1.1 usscz2-edge-lx-004.ts.apple.com (acdn/14319.5), https/1.1 usscz2-edge-bx-033.ts.apple.com (acdn/14319.5)
Via: http/1.1 ussjc2-vp-vst-009.ts.apple.com (acdn/14319.5), http/1.1 ussjc2-vp-vfe-002.ts.apple.com (acdn/14319.5), https/1.1 usscz2-edge-lx-004.ts.apple.com (acdn/14319.5), https/1.1 usscz2-edge-bx-033.ts.apple.com (acdn/14319.5)

which return file content in apple-app-site-association with response code 200.

Some not work CDN nodes:

< Via: http/1.1 jptyo5-vp-vst-014.ts.apple.com (acdn/84.14362), https/1.1 jptyo5-vp-vfe-006.ts.apple.com (acdn/84.14362)

which return Not Found with response code 404.

When use Asia based IPs, we also got some error response header:

< Apple-Failure-Details: {"cause":"context deadline exceeded (Client.Timeout exceeded while awaiting headers)"}
< Apple-Failure-Reason: SWCERR00301 Timeout

Example request with IP in Japan:

> GET /a/v1/ourdomain.com HTTP/1.1
> Host: app-site-association.cdn-apple.com
> User-Agent: curl/7.86.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 404 Not Found
< Content-Type: text/plain; charset=utf-8
< Content-Length: 10
< Connection: keep-alive
< Server: nginx
< Date: Mon, 21 Aug 2023 12:45:02 GMT
< Expires: Mon, 21 Aug 2023 12:45:12 GMT
< Age: 608
< Apple-Failure-Details: {"cause":"context deadline exceeded (Client.Timeout exceeded while awaiting headers)"}
< Apple-Failure-Reason: SWCERR00301 Timeout
< Apple-From: https://ourdomain.com/.well-known/apple-app-site-association
< Apple-Try-Direct: true
< Via: http/1.1 jptyo5-vp-vst-014.ts.apple.com (acdn/84.14362), https/1.1 jptyo5-vp-vfe-006.ts.apple.com (acdn/84.14362)
< X-Cache: MISS KS-CLOUD
< CDNUUID: 03f2e102-fa68-4a5f-bc93-0e151a3dfc64-773587498
< x-link-via: ziyct01:443;xymp07:443;gzun11:443;xg02:443;
< x-b2f-cs-cache: no-cache
< X-Cache-Status: MISS from KS-CLOUD-XG-02-03
< X-Cache-Status: MISS from KS-CLOUD-GZ-UN-11-06
< X-Cache-Status: MISS from KS-CLOUD-XY-MP-07-15
< X-Cache-Status: MISS from KS-CLOUD-ZIY-CT-01-09
< CDN-Server: KSFTF
< X-KSC-Request-ID: 0afe4d526afd86918a55a0640d2b75f3
< X-Cdn-Request-ID: 0afe4d526afd86918a55a0640d2b75f3
<
Not Found