MatterSupport extension MatterAddDeviceExtensionRequestHandler Thread device failure

I am using the MatterSupport extension to commission devices for my own ecosystem. I use the extension to do the initial connection to the device (BLE, PASE, bring device onto wifi/thread) and then use the method

commissionDevice(in home: MatterAddDeviceRequest.Home?, onboardingPayload: String, commissioningID: UUID)

in MatterAddDeviceExtensionRequestHandler to send a request to my own hub on the local network where it then connects to the device via wifi/thread and fully commissions the device. This flow is working correctly for wifi enabled devices, however it fails for thread devices. For some context, I am using my own border router (and have already added the router's credentials to the phone using THClient's storeCredentials). Here are some device-specific results:

• ESP32 (WIFI): successful commission
• ESP32 (THREAD): failure
• Matter Certified ONVIS smart plug (THREAD): failure

The ESP32's are running espressif matter examples. Example border router is a running OTBR docker container

I believe that the entire PASE session is established and the device gets onto the thread network, but the process seems to stall after that. I have verified that selectThreadNetwork(...) and validateDeviceCredential(...) get called but the commissioning process seems to stall before it can get to commissionDevice(...)

I am limited to 7k characters, but I'll try to include as many relevant log lines as I can near the error if anyone has any ideas. I've already created a bug report with ID: FB18985348 which includes the full logs from the esp32 and a sysdiagnose from an iPhone 12 Pro (iOS 18.5) using the following log profiles:

• Home app/HomeKit
• HomeThread
• ThreadNetwork

When commissioning directly from my hub, the entire commissioning completes successfully 100% of the time. This failure only happens when I use MatterSupport to initiate commissioning for Matter over Thread devices specifically.

Very condensed homed log overview for uncertified ESP32 thread example

Next: 'SecurePairing' -> 'ReadCommissioningInfo'
Step: 'ReadCommissioningInfo'
Sending read requests for commissioning information
NetworkCommissioning Features: has Thread. endpointid = 0
<MTRDeviceController_Concrete: ..., uuid: F9BB9F53-BF73-4B82-B00B-045E7709530E...> completed for nodeID 0x0000000055d193ec with status: Success
✔ 'ReadCommissioningInfo'
Next: 'ReadCommissioningInfo' -> 'ArmFailSafe'
Step: 'ArmFailSafe'
✔ 'ArmFailSafe'
Next: 'ArmFailSafe' -> 'ConfigRegulatory'
Step: 'ConfigRegulatory'
✔ 'ConfigRegulatory'
Next: 'ConfigRegulatory' -> 'ConfigureTCAcknowledgments'
Step: 'ConfigureTCAcknowledgments'
✔ 'ConfigureTCAcknowledgments'
Next: 'ConfigureTCAcknowledgments' -> 'SendPAICertificateRequest'
Step: 'SendPAICertificateRequest'
✔ 'SendPAICertificateRequest'
Next: 'SendPAICertificateRequest' -> 'SendDACCertificateRequest'
Step: 'SendDACCertificateRequest'
✔ 'SendDACCertificateRequest'
Next: 'SendDACCertificateRequest' -> 'SendAttestationRequest'
Step: 'SendAttestationRequest'
✔ 'SendAttestationRequest'
Next: 'SendAttestationRequest' -> 'AttestationVerification'
Step: 'AttestationVerification'
Error on commissioning step 'AttestationVerification': Internal error
Next: 'AttestationVerification' -> 'AttestationRevocationCheck'
Step: 'AttestationRevocationCheck' (with error)
Device attestation error: Integrity check failed.
Continue commissioning (ignore attestation failure: YES)
✔ 'AttestationRevocationCheck'
Next: 'AttestationRevocationCheck' -> 'SendOpCertSigningRequest'
Step: 'SendOpCertSigningRequest'
✔ 'SendOpCertSigningRequest'
Next: 'SendOpCertSigningRequest' -> 'ValidateCSR'
Step: 'ValidateCSR'
✔ 'ValidateCSR'
Next: 'ValidateCSR' -> 'GenerateNOCChain'
Step: 'GenerateNOCChain'
✔ 'GenerateNOCChain'
Step: 'SendTrustedRootCert'
✔ 'SendTrustedRootCert'
Next: 'SendTrustedRootCert' -> 'SendNOC'
Step: 'SendNOC'
✔ 'SendNOC'
Next: 'SendNOC' -> 'ThreadNetworkSetup'
Step: 'ThreadNetworkSetup'
✔ 'ThreadNetworkSetup'
Next: 'ThreadNetworkSetup' -> 'FailsafeBeforeThreadEnable'
Step: 'FailsafeBeforeThreadEnable'
✔ 'FailsafeBeforeThreadEnable'
Next: 'FailsafeBeforeThreadEnable' -> 'ThreadNetworkEnable'
Step: 'ThreadNetworkEnable'
✔ 'ThreadNetworkEnable'
Next: 'ThreadNetworkEnable' -> 'kEvictPreviousCaseSessions'
Step: 'kEvictPreviousCaseSessions'
✔ 'kEvictPreviousCaseSessions'
Next: 'kEvictPreviousCaseSessions' -> 'kFindOperationalForStayActive'
Step: 'kFindOperationalForStayActive'
Error: Timeout
Next: 'kFindOperationalForStayActive' -> 'Cleanup'
Step: 'Cleanup' (with timeout error)
✔ 'Cleanup'
Commissioning complete for node ID 0x0000000055D193EC with timeout error