On FreeBSD the stock code will attempt to expand the interface MTU any time a packet is to be sent that exceeds the current MTU. This results in a down/up on the interface that is wildly disruptive to existing services on that adapter and, eventually, is likely to run into MTU limits and start logging failures, even with jumbo-frame capable adapters. Thus if compiling on a FreeBSD machine disable this capability. Tested against 12.3-STABLE and 13.1-STABLE on v4.38-9760 from the FreeBSD ports tree but likely applies here as well; see bug report https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=267178