Set username (PATCH request acconuts/update_credentials) fails with 422 No event to update

Possibly related to:

• Reset password is not working — soapbox#1004
• User preferences aren't saved — ditto#46

Observed on ditto.pub and henhouse.social:

You were granted the name [username]@[hostname]

Set name to [username]@[hostname]

Button triggers a PATCH to [hostname]/api/v1/accounts/update_credentials which fails with status 422 and response: {"error":"No event to update"}

Same thing occurs when setting the username from [hostname]/settings/profile and [hostname]/settings/identity

Strangely, the homepage still says:

Your username request is under review.

Verify credentials responds with the following:

{
  "id": "…",
  "acct": "…",
  "avatar": "[hostname]/images/avi.png",
  "avatar_static": "[hostname]/images/avi.png",
  "bot": false,
  "created_at": "…",
  "discoverable": true,
  "display_name": "",
  "emojis": [],
  "fields": [],
  "follow_requests_count": 0,
  "followers_count": 0,
  "following_count": 0,
  "fqn": "…",
  "header": "[hostname]/images/banner.png",
  "header_static": "[hostname]/images/banner.png",
  "last_status_at": null,
  "locked": false,
  "note": "",
  "roles": [],
  "source": {
    "fields": [],
    "language": "",
    "note": "",
    "privacy": "public",
    "sensitive": false,
    "follow_requests_count": 0,
    "nostr": {},
    "ditto": {
      "captcha_solved": false
    }
  },
  "statuses_count": 0,
  "uri": "[hostname]/users/[pubkey]",
  "url": "[hostname]/@[pubkey]",
  "username": "…",
  "ditto": {
    "accepts_zaps": false,
    "external_url": "https://njump.me/…",
    "streak": {
      "days": 0,
      "start": null,
      "end": null,
      "expires": null
    }
  },
  "pleroma": {
    "deactivated": false,
    "is_admin": false,
    "is_moderator": false,
    "is_suggested": false,
    "is_local": false,
    "settings_store": {
      "soapbox_fe": {
        "notifications": {
          "quickFilter": {
            "active": "all"
          }
        },
        "dismissedSettingsNotifications": [
          "needsNip05"
        ]
      }
    },
    "tags": []
  },
  "nostr": {
    "pubkey": "…"
  }
}