I have just upgraded my FinSpy on my testing environment to 4.40. I tested by infecting a new laptop, the target appear online on the agent laptop. Shortly after a few minutes, the target went offline even though the target laptop is still up. If I do a reboot or restart the networking services on the master server, the target will goes back online. But after a few minutes, it went back offline again. Additional info: The relay server is up and it did sent syn packet to the server. On the master server, the status using netstat is sync_received. From Finspy master log: 

INFO: TIO: target 0x666A106C comes online Trojan: test345 Comp-Name: USER01-PC Inst-Mode: Kernel

INFO: Unable to add new entry for Trojan 37236673 to Crypto Key List: there is already an entry

WARNING: Unknown Meta-data 0xFE3A80 from target 0x666A106C
INFO: TIO: Timeout, Master hasnt got heart beats from target 0x666A196C for longer than 32 seconds, set it to offline