Developing a client-server application, but does something seem to go wrong with sending / receiving data? WireShark or tshark may help you.
With these applications you can view the traffic between your client and server. This way you can see what kind of data your client sends / receives or your server receives / sends.
This way you can find out if, for example, a character is sent too much, formatting is not good, connection is not completed i.v. a certificate problem, …., …., and much more.