Hi Michael:
It is not easy to find the root cause from your information, maybe it is a tcp ip task memory issue,
I suggest your try to modifying the initial RTCS parameters as follows to see whether it helps
/* runtime RTCS configuration */
_RTCSPCB_init = 12;
_RTCSPCB_grow = 2;
_RTCSPCB_max = 20;
_RTCS_msgpool_init = 12;
_RTCS_msgpool_grow = 2;
_RTCS_msgpool_max = 20;
_RTCS_socket_part_init = 12;
_RTCS_socket_part_grow = 2;
_RTCS_socket_part_max = 20;
Regards
Daniel