Swarm remote blades failing to connect

Some blades aren’t connecting properly, they keep trying to connect but failing. This is what the log says:

17:29:57: [Connect] Successfully opened a remote connection with B21
17:30:00: [EndJobSpecification] Tried to begin the job on a valid remote connection, but failed
17:30:00: [CloseConnection] Closing connection 22C7C32E using handle 22C7C32E
17:30:00: [CloseConnection] Connection confirmed for disconnection 22C7C32E
17:30:00: [CloseConnection] Closing bi-directional remote connection (22C7C32E)
17:30:00: [CloseConnection] Closing connection 22C7C32E using handle 22C7C32E
17:30:00: [CloseConnection] Connection already being disconnected, nothing to do 22C7C32E
17:30:00: [CloseConnection] Connection disconnected 22C7C32E
17:30:00: [EndJobSpecification] Tried to begin the job on a valid remote connection, but failed
17:30:00: [CloseConnection] Closing connection 22C7C32D using handle 22C7C32D
17:30:00: [CloseConnection] Connection confirmed for disconnection 22C7C32D
17:30:00: [CloseConnection] Closing bi-directional remote connection (22C7C32D)
17:30:00: [CloseConnection] Closing connection 22C7C32D using handle 22C7C32D
17:30:00: [CloseConnection] Connection already being disconnected, nothing to do 22C7C32D
17:30:00: [CloseConnection] Connection disconnected 22C7C32D
17:30:01: [MaintainConnections] Remote connection has closed (22C7C32E)
17:30:01: [MaintainConnections] Remote connection has closed (22C7C32D)
17:30:01: [MaintainConnections] Removed connection 22C7C32E
17:30:01: [MaintainConnections] Removed connection 22C7C32D
17:30:02: [Connect] Successfully opened a remote connection with B27
17:30:02: [EndJobSpecification] Tried to begin the job on a valid remote connection, but failed
17:30:02: [CloseConnection] Closing connection 22C7C32B using handle 22C7C32B
17:30:02: [CloseConnection] Connection confirmed for disconnection 22C7C32B
17:30:02: [CloseConnection] Closing bi-directional remote connection (22C7C32B)
17:30:02: [EndJobSpecification] Tried to begin the job on a valid remote connection, but failed
17:30:02: [CloseConnection] Closing connection 22C7C32F using handle 22C7C32F