TCP server recieving once


I will explain my problem below:

I have the uBlox c027 as a TCP server and I’m running it in a seperate thread. also I have another thread which is a UDP client. The TCP server thread will send a signal to the udp thread to start sending the data or close the socket regarding the data that I’m sending from the TCP client (my PC).

When I’m sending my data from the TCP client, it seems that it works only once. when I tried to send another msg, the TCP server(ublox) not recieving.

Please advise