I created a brand new app from stratch using gradio sdk version 6.19.0. Deployed successfully.

Results

Test 1 (works)

Direct access to https://[space-subdomain].hf.space

Test 2 (works)

Direct access to https://[space-subdomain].hf.space/config

Test 3 (works)

iFrame works.

Test 4 (fails)

Embedding as web component with subdomain fails.

<gradio-app src="https://[space-subdomain].hf.space">

Test 5 (fails)

Embedding web compontent with owner/space fails.

<gradio-app space="<owner>/<space_name>">

Test 6 (fails)

Calling the URL below will fail:

https://huggingface.co/api/spaces/by-subdomain/[subdomain]

Result:

HTTP/2 400
content-type: application/json; charset=utf-8
content-length: 89
date: Tue, 23 Jun 2026 04:39:50 GMT
etag: W/"59-W4Wj6ETpoa9k7JmLJHDRpTMRfQU"
x-powered-by: huggingface-moon
x-request-id: Root=1-6a3a0e16-3c72985c5f7ccbf1605d998f
ratelimit: "api";r=499;t=103
ratelimit-policy: "fixed window";"api";q=500;w=300
cross-origin-opener-policy: same-origin
referrer-policy: strict-origin-when-cross-origin
access-control-max-age: 86400
access-control-allow-origin: https://huggingface.co
vary: Origin
access-control-expose-headers: X-Repo-Commit,X-Request-Id,X-Error-Code,X-Error-Message,X-Total-Count,ETag,Link,Accept-Ranges,Content-Range,X-Linked-Size,X-Linked-ETag,X-Xet-Hash
x-error-message: Invalid repo name: owner/space - repo name includes an url-encoded slash
x-cache: Error from cloudfront
via: 1.1 744a1a944313f4cfdfc83fe056d50e50.cloudfront.net (CloudFront)
x-amz-cf-pop: SIN2-P7
x-amz-cf-id: b56oFSz97_nflnS2BDFZGFm1wwInQ2B_HuKJVIlGNwqTJ7XaPg_Gdg==

{"error":"Invalid repo name: owner/space - repo name includes an url-encoded slash"}

Test 7 (works)

https://huggingface.co/api/spaces/owner/space

I’m stuck on what to try next here!