Swarm Agent Stuck on Lighting Build

Hi guys, long time lurker first time posting!

We’re having a problem with building the lighting in our level since 4.25. It seems to get stuck when computing the light from the Sun&Sky. We have tried removing the saved data and letting unreal rebuild the folder, reducing light emission and bounce settings, turning off shadows on large amounts of objects and so on. The overdraw and lighting complexity maps are all green, there is a single light source from the sun&sky. The landscape is pretty large but nothing compared to a modern game. Even with all these changes were not getting beyond 0.00% in 4-5 hours of light building so something must be broken. The full log created by SwarmAgent is below:

12:13:33 PM: Starting up SwarmAgent …
12:13:33 PM: … registering SwarmAgent with remoting service
12:13:33 PM: … registering SwarmAgent network channels
12:13:33 PM: … initializing SwarmAgent
12:13:33 PM: … certificate check has failed
12:13:33 PM: … initializing cache
12:13:33 PM: … using cache folder ‘C:/Users/*****/AppData/Local/UnrealEngine/4.25/Saved/Swarm\SwarmCache’
12:13:33 PM: … recreating SwarmAgent cache staging area
12:13:33 PM: … initializing connection to SwarmCoordinator
12:13:33 PM: … using SwarmCoordinator on RENDER-01
12:13:33 PM: … SwarmCoordinator successfully initialized
12:13:33 PM: … initializing local performance monitoring subsystem
12:13:39 PM: … initialization successful, SwarmAgent now running
12:13:41 PM: [Interface:TryOpenConnection] Local connection established
12:13:42 PM: [Job] Accepted Job 0740F0F7-4E58B1C9-9A4848BA-EF4A8FF5
12:14:01 PM: [Job] Launched Job UnrealLightmass_2020-07-14_02-06-22_1126656-64bit.exe
12:14:01 PM: [Job] PID is 23728
12:14:01 PM: [Job] GUID is “0740F0F7-4E58B1C9-9A4848BA-EF4A8FF5”
12:14:01 PM: LogLightmass: Display: Lightmass Win64 started on: HANNA. Command-line: 0740F0F74E58B1C99A4848BAEF4A8FF5
12:14:01 PM: Failed to determine engine directory: Defaulting to …/…/…/Engine/
12:14:01 PM: Failed to load ‘aqProf.dll’ (GetLastError=126)
12:14:01 PM: File ‘aqProf.dll’ does not exist
12:14:01 PM: Failed to load ‘VtuneApi.dll’ (GetLastError=126)
12:14:01 PM: File ‘VtuneApi.dll’ does not exist
12:14:01 PM: Failed to load ‘VtuneApi32e.dll’ (GetLastError=126)
12:14:01 PM: File ‘VtuneApi32e.dll’ does not exist
12:14:01 PM: Lightmass Win64 started on: HANNA. Command-line: 0740F0F74E58B1C99A4848BAEF4A8FF5
12:14:01 PM: LogLightmass: Display: Processing scene GUID: 0740F0F74E58B1C99A4848BAEF4A8FF5 with 6 threads
12:14:01 PM: Processing scene GUID: 0740F0F74E58B1C99A4848BAEF4A8FF5 with 6 threads
12:14:01 PM: Building static lighting…
12:14:01 PM: [OpenConnection] Registering TCP channel …
12:14:01 PM: [OpenConnection] Connecting to agent …
12:14:01 PM: [TryOpenConnection] Testing the Agent
12:14:01 PM: [TryOpenConnection] Opening Connection to Agent
12:14:01 PM: [TryOpenConnection] Local Process ID is 23728
12:14:01 PM: [Job] Found a parent connection for PID 23728
12:14:01 PM: [Job] 5F342960 → 1F3F4A01
12:14:01 PM: [Interface:TryOpenConnection] Local connection established
12:14:38 PM: Measured CPU frequency: 4.01 GHz
12:14:38 PM: FStaticLightingSystem started using GKDOPMaxTrisPerLeaf: 4
12:14:38 PM: Number of texture mappings: 46594
12:14:38 PM: Number of fluid mappings: 0
12:14:38 PM: Number of landscape mappings: 256
12:14:38 PM: Number of BSP mappings: 0
12:14:38 PM: Number of static mesh instance mappings: 46594
12:14:45 PM: Scene surface area calculated at 715252.438 million units (17.065% of the estimated 4191233.750 million units)
12:14:45 PM: Importance volume surface area calculated at 5217.159 million units (40.485% of the estimated 12886.660 million units)
12:14:45 PM: Clamped the number of indirect photon paths to 20000.
12:14:49 PM: Embree Build 3.9s
12:14:49 PM:
12:14:49 PM:
12:14:49 PM: Collision Mesh Overview:
12:14:49 PM: Num Triangles : 28314802
12:14:49 PM: MeshInfos : 3.9Mb
12:14:49 PM: UVs : 238.0Mb
12:14:49 PM: LightmapUVs : 238.0Mb
12:14:49 PM: Embree Used Memory : 2022.8Mb
12:14:49 PM:
12:14:49 PM:
12:14:49 PM: Processing…
12:14:50 PM: EmitDirectPhotons complete, 1.128 million photons emitted in 0.4 seconds
12:14:53 PM: Built photon segment map in 0.1 seconds
12:14:53 PM: EmitIndirectPhotons complete, 3.130 million photons emitted in 1.8 seconds
12:14:53 PM: Marking Irradiance Photons complete, 0.250 million photons marked in 0.1 seconds
12:23:01 PM: Caching Irradiance Photons complete, 1069.308 million cache samples in 487.8 seconds
12:23:07 PM: Calculate Irradiance Photons complete, 0.203 million irradiance calculations in 6.0 seconds
2:43:43 PM: [CloseConnection] Closing connection 5F342960 using handle 5F342960
2:43:44 PM: [CloseConnection] Connection confirmed for disconnection 5F342960
2:43:44 PM: [CloseConnection] Closing orphaned Job (0740F0F7-4E58B1C9-9A4848BA-EF4A8FF5)
2:43:44 PM: [Job] Job has failed! Job is closed while Tasks are still PENDING
2:43:44 PM: [CloseConnection] Orphaning local connection (5F342960 is the parent of 1F3F4A01)
2:43:44 PM: [CloseConnection] Connection disconnected 5F342960
2:43:44 PM: [GetMessage] Safely returning to 5F342960 with no message
2:43:45 PM: [MaintainConnections] Local connection has closed (5F342960)
2:43:45 PM: [MaintainConnections] Removed connection 5F342960
2:43:45 PM: [Maintain Jobs] Killing rogue Job “0740F0F7-4E58B1C9-9A4848BA-EF4A8FF5”
2:43:48 PM: [MaintainConnections] Detected dropped local connection, cleaning up (1F3F4A01)
2:43:48 PM: [CloseConnection] Closing connection 1F3F4A01 using handle 1F3F4A01
2:43:48 PM: [CloseConnection] Connection confirmed for disconnection 1F3F4A01
2:43:48 PM: [CloseConnection] Connection disconnected 1F3F4A01
2:43:48 PM: [GetMessage] Safely returning to 1F3F4A01 with no message
2:43:51 PM: [MaintainConnections] Local connection has closed (1F3F4A01)
2:43:51 PM: [MaintainConnections] Removed connection 1F3F4A01
2:43:51 PM: [MaintainConnections] All connections have closed

Please help. We plan on adding many more objects to this open world and cant have build times like this.