Custom domain stuck in "Deleting" status on Static Web App (Standard plan) — cannot remove via Portal, CLI, or ARM REST; second, unrelated domain hit the identical bug

I have tried to add custom domains via the Portal. CNAME was confirmed resolving correctly beforehand. It failed with "An unknown error has occurred while adding your custom domain." and got left attached with status: "Deleting". No CAA record involved — ruled that out, and we've added custom domains to this same root domain successfully before on other apps.

Tried to clear it three ways, none worked — record is unchanged in hostname list after each:

Portal delete (spun indefinitely)

az staticwebapp hostname delete (CLI returns Operation returned an invalid status 'OK')

Raw ARM DELETE call (no error, no effect)

To rule out a domain-specific fluke, tried a second, previously-untouched subdomain on the same app. Same generic error. It landed in status: "Failed" (clean terminal state) — but attempting to delete that one flipped it into the same "Deleting" limbo too.

Current state: both custom domains are stuck in Deleting on the static web app, unremovable via any client-side path. Looks like a corrupted backend state on this resource, not a DNS or domain-specific issue.

Similar to this resolved thread — same symptom pattern, though that was an apex domain on http-token validation; ours is a subdomain on CNAME. The --environment-name retry suggested there doesn't apply here — not a valid parameter on az staticwebapp hostname delete in CLI 2.88.0.

Could someone force-clear these two stuck records so a custom domain can be re-added? Also just upgraded to paid support to open a ticket but couldn't get one submitted — posting here as a fallback.