Azure Storage and Front Door returns Stale with Caching Disabled

I’m serving Azure Blob Storage content through an Azure Front Door endpoint - endwith.azurefd.net with Enable caching DISABLED.

After overwriting a blob at the same URL, requests through Front Door sometimes return the previous content. Requests made seconds apart to different endpoint IP addresses return different versions of the same file, with x-cache: TCP_HIT on all responses.

This also occurs with curl, so the behavior is reproducible outside the browser.

Repro:

1. Create an Azure Front Door route pointing to Azure Blob Storage, with “Enable caching” unchecked from the beginning.
2. Upload a text blob.
3. Overwrite the blob with updated content, keeping the same URL.
4. Request the same path through different endpoint IP addresses, using the same Front Door Host header.

Output:

$ curl https://150.171.110.8/jk/abc/test.txt -v -H 'Host: xxx.azurefd.net' -k
< HTTP/2 200 
< date: Mon, 05 Oct 2026 17:06:04 GMT
< content-type: text/plain
< content-length: 9
< last-modified: Mon, 05 Oct 2026 16:15:26 GMT
< etag: "0x8DF22FBDE0B6B7C"
< x-ms-request-id: 9284fff3-801e-0029-3ee5-5433f8000000
< x-ms-version: 2018-03-28
< x-azure-ref: 20261005T170604Z-1869b9ffdbb7krvchC1SN1qbz400000020tg000000005m70
< x-fd-int-roxy-purgeid: 0
< x-cache: TCP_HIT
< accept-ranges: bytes
< 
12345678

$ curl https://150.171.110.177/jk/abc/test.txt -v -H 'Host: xxx.azurefd.net' -k
< HTTP/2 200 
< date: Mon, 05 Oct 2026 17:06:10 GMT
< content-type: text/plain
< content-length: 9
< last-modified: Mon, 05 Oct 2026 16:15:26 GMT
< etag: "0x8DF22FBDE0B6B7C"
< x-ms-request-id: 9284fff3-801e-0029-3ee5-5433f8000000
< x-ms-version: 2018-03-28
< x-azure-ref: 20261005T170610Z-r167b4f69fd8mfd2hC1SN1rxan0000000900000000005u9m
< x-fd-int-roxy-purgeid: 0
< x-cache: TCP_HIT
< accept-ranges: bytes
< 
12345678

$ curl https://150.171.110.179/jk/abc/test.txt -v -H 'Host: xxx.azurefd.net' -k
< HTTP/2 200 
< date: Mon, 05 Oct 2026 17:06:17 GMT
< content-type: text/plain
< content-length: 10
< last-modified: Mon, 05 Oct 2026 16:20:27 GMT
< etag: "0x8DF22FC9170246E"
< x-ms-request-id: c921cfb2-e01e-003f-78e5-54c52f000000
< x-ms-version: 2018-03-28
< x-azure-ref: 20261005T170617Z-1585799c5745b87xhC1DFWqf2w00000010v000000000ddkn
< x-fd-int-roxy-purgeid: 0
< x-cache: TCP_HIT
< x-cache-info: L1_T2
< accept-ranges: bytes
< 
123456789