rcsocks does not always exchange data

[KVPV]

I run it like this: ./rcsocks -p 10001 -l 5001 -b

Correct work:
[+] The reverse client connects successfully to 10001 and listens.
[+] I am successfully connecting to 5001 and sending data.
[+] rcsocks - successfully binds two clients.

Sometimes I get problems like this:
[-] The reverse client receives 0 data from port 10001.
[-] The socket with my connection to port 5001 is closed.

I have to kill the process and start it over and over again until I get it working properly.

Reverse client - this Socks5-client written in C ++ for Windows.