My 'Send' command is not blocking when it should, and instead crashes the socket connection

My Client successfully connects to the Server and starts sending data using the 'Send' Winsock API. It continues sending data at a rate faster than the Server can process it. On Windows 10, the socket behaves as advertised, and the 'Send' blocks until the Server catches up. On Windows 11, the 'Send' does NOT block and crashes the socket (10053 error code) when (apparently) the TCP/IP buffer overflows. It sends anywhere from 700MB to nearly 2GB before this happens. I searched high and low for a setting that's different between the two, or something I'm not doing properly, but have found nothing. Any ideas anyone?