Serverless SQL pool database stuck in RECOVERY_PENDING even after CMK and identity fixes

I have a Synapse workspace where one of my serverless SQL databases is stuck in RECOVERY_PENDING, and I’m unable to clear the error through any customer‑accessible method. I also do not have the ability to open a support ticket, so I’m posting here hoping a Microsoft engineer can assist.

Environment details

• Workspace: synw‑data‑ncas
• Resource group: rg‑data‑ncas‑core
• Region: (same region as Key Vault — can add if needed)
• Encryption: Customer‑Managed Key (CMK) enabled at workspace level
• Key Vault: kv‑lsst
• Serverless SQL pool: built‑in
• Identity: tested with both System‑Assigned MI and a User‑Assigned MI (UAMI)

Workspace keys

Output of az synapse workspace key list:

[
  {
    "name": "default",
    "keyVaultUrl": "https://kv-lsst.vault.azure.net/keys/workspaceEncryption",
    "isActiveCmk": false
  },
  {
    "name": "45988138-245c-4d5b-acad-77bb92e9e00f",
    "keyVaultUrl": "https://kv-lsst.vault.azure.net/keys/tempEncryption",
    "isActiveCmk": true
  }
]

Database states

From SELECT name, state_desc, is_encrypted FROM sys.databases;:

master         ONLINE            False
NCAS_Archive   RECOVERY_PENDING  True

So the built-in master database is healthy but NCAS_Archive cannot be brought online.

Actions I have already tried (complete list)

1. Switched workspace CMK between the original key (workspaceEncryption) and temporary key (tempEncryption).

• Synapse only allows versionless Key Vault URLs for workspace keys, so I re‑registered with the correct format.

2. Confirmed Key Vault configuration

• Key enabled
• Purge protection enabled
• Soft delete enabled
• Verified validity/expiration dates

3. Validated Key Vault permissions

• Workspace identity granted get, wrapKey, unwrapKey
• Permissions tested under both System‑Assigned MI and a UAMI with Key Vault Crypto Officer*

4. Switched workspace identity

• Tested using UAMI instead of System‑Assigned MI
• Re‑granted KV permissions after switching
• No change in behavior

5. Checked serverless connectivity and storage access

• Storage account reachable
• Other workspace components operational
• Only NCAS_Archive fails recovery

Current symptoms

• master database loads correctly and is ONLINE
• Only NCAS_Archive is stuck in RECOVERY_PENDING
• No customer operations (CMK, MI, KV, SQL commands) have changed its state
• The database cannot be dropped, recovered, or repaired by any exposed tool

Why I'm posting here

There is a known scenario where serverless SQL pools get stuck in RECOVERY_PENDING due to backend issues with workspace metadata or the managed identity certificate, which can only be corrected internally by Microsoft. I believe I may be in that situation. Since I cannot open a support ticket, I’m requesting assistance from a Microsoft engineer to:

• Inspect the backend state of the serverless SQL pool
• Validate the workspace encryption metadata
• Reset any stuck identities/certificates if necessary
• Manually force recovery of the NCAS_Archive database if required

Any help would be greatly appreciated. I’ve exhausted all user‑accessible recovery options. Thank you.