Unable to Establish PDU Session between gNB and AMF - [NETWORK_FAILURE] Error

[TWISTlab01]

I am encountering an issue with establishing a PDU (Packet Data Unit) Session between the gNB (gNodeB) and the AMF (Access and Mobility Management Function) in my Open5GS setup. The logs indicate an error with the message [NETWORK_FAILURE].

Here is a summary of the error messages from the logs:

[2024-03-18 12:09:30.235] [nas] [info] UE switches to state [MM-DEREGISTERED/PLMN-SEARCH]
[2024-03-18 12:09:30.235] [rrc] [debug] New signal detected for cell[1], total [1] cells in coverage
[2024-03-18 12:09:30.235] [nas] [info] Selected plmn[001/01]
[2024-03-18 12:09:30.235] [rrc] [info] Selected cell plmn[001/01] tac[1] category[SUITABLE]
[2024-03-18 12:09:30.235] [nas] [info] UE switches to state [MM-DEREGISTERED/PS]
[2024-03-18 12:09:30.235] [nas] [info] UE switches to state [MM-DEREGISTERED/NORMAL-SERVICE]
[2024-03-18 12:09:30.235] [nas] [debug] Initial registration required due to [MM-DEREG-NORMAL-SERVICE]
[2024-03-18 12:09:30.235] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:30.235] [nas] [debug] Sending Initial Registration
[2024-03-18 12:09:30.236] [nas] [info] UE switches to state [MM-REGISTER-INITIATED]
[2024-03-18 12:09:30.236] [rrc] [debug] Sending RRC Setup Request
[2024-03-18 12:09:30.237] [rrc] [info] RRC connection established
[2024-03-18 12:09:30.237] [rrc] [info] UE switches to state [RRC-CONNECTED]
[2024-03-18 12:09:30.237] [nas] [info] UE switches to state [CM-CONNECTED]
[2024-03-18 12:09:30.252] [nas] [debug] Authentication Request received
[2024-03-18 12:09:30.252] [nas] [debug] Received SQN [0000000001A1]
[2024-03-18 12:09:30.252] [nas] [debug] SQN-MS [000000000000]
[2024-03-18 12:09:30.259] [nas] [debug] Security Mode Command received
[2024-03-18 12:09:30.259] [nas] [debug] Selected integrity[2] ciphering[0]
[2024-03-18 12:09:30.278] [nas] [debug] Registration accept received
[2024-03-18 12:09:30.278] [nas] [info] UE switches to state [MM-REGISTERED/NORMAL-SERVICE]
[2024-03-18 12:09:30.278] [nas] [debug] Sending Registration Complete
[2024-03-18 12:09:30.278] [nas] [info] Initial Registration is successful
[2024-03-18 12:09:30.278] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:30.278] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:30.481] [nas] [debug] Configuration Update Command received
[2024-03-18 12:09:30.501] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:31.335] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:31.335] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:31.354] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:31.562] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:31.562] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:31.579] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:32.436] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:32.436] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:32.453] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:33.537] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:33.537] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:33.559] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:34.638] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:34.638] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:34.655] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:35.739] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:35.739] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:35.768] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:36.840] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:36.840] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:36.858] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:37.941] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:37.941] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:37.965] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:39.042] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:39.042] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:39.058] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:40.143] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:40.143] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:40.159] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:41.244] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:41.244] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:41.261] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:41.562] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:41.562] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:41.581] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:42.345] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:42.345] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:42.363] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:43.446] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:43.446] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:43.466] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]
[2024-03-18 12:09:44.547] [nas] [debug] Sending PDU Session Establishment Request
[2024-03-18 12:09:44.547] [nas] [debug] UAC access attempt is allowed for identity[0], category[MO_sig]
[2024-03-18 12:09:44.566] [nas] [error] PDU Session Establishment Reject received [NETWORK_FAILURE]

Steps I have taken so far:

Checked Network Connectivity: Ensured there are no network connectivity issues between the gNB and the AMF.
Reviewed Configuration: Verified the configuration of both the gNB and the AMF to ensure correctness.

Despite these efforts, I am still unable to resolve the issue. I would appreciate any assistance or insights on how to troubleshoot and resolve this problem.