WIZ550S2E UDP socket close error

Since the version 1.1.0 I encountered such a problem:
AT > [S]
AT+MSTAT > [S,1.1.2]
AT+NSET=S,,,, > [S]
AT+NOPEN=U,6102 > [S,0]
AT+NSEND=0,9,,6100 xxxxxxxxx > [W,0] mis [S,0] !!!
AT+NCLOSE=0 > [F,7]

I noticed that in the new version in function sendto file socket.c the string was deleted:
if( (sock_io_mode & (1<<sn)) ) return SOCK_BUSY;

When I returned the string, the error disappeared:

AT+NSEND=0,9,,6100 xxxxxxxxx > [W,0] [S,0]

I will fix the problem.