HAP‑Token‑Update‑Request if accessory cannot save new token

AFAIK, if an accessory fails to correctly store the new token during the HAP-Token-Update-Request process then its local pairing data will be inconsistent with what the controller (e.g., the Home app) expects. In that case, the accessory will indeed, as you suspected, fail future pair resume or re-add attempts because the Home app’s stored token won’t match what the accessory has on record. From the HomeKit perspective, this looks like a device that’s either “already paired” to another controller or simply unreachable during setup.

To recover, the accessory typically needs to reset its pairing state and clear all stored tokens. In other words, performing a factory reset or at least a HomeKit configuration reset will erase the corrupted or partial token data. Once that’s done, the Home app should be able to see the device as new and allow it to be added again normally.

It looks like the HomeKit pairing process failed during the MFi (Made for iPhone) token authentication stage. The log you shared shows the accessory successfully accessed its stored provisioning tokens (`kSDKKeyValueStoreKey_Provisioning_MFiTokenUUID` and `MFiToken`), but something likely went wrong right after this — possibly due to a stale or invalid MFi token remaining after your factory reset. Even though the accessory attempted to restore itself, the BLE session probably terminated before a valid authentication response could be completed.

Here’s some final suggestions on what you can try:

• Some devices retain MFi tokens in non-volatile memory even after a “soft” reset. Check the manufacturer’s instructions for a complete reset that clears all HomeKit and MFi credentials.
• Restart the iPhone and the accessory before reattempting pairing.
• If it still shows up, try forgetting the accessory in HomeKit. Then retry pairing from scratch.
• If the issue persists, contact the accessory vendor for a reissued token.