F5 Monitor tcp_half_open is getting down error Ipv4 address mismatch

As of A.D. 2020, the "tcp_half_open" monitor type is actually needed about as often as you need your vacuum-tube tester. Years ago, a few quirky server-side resources required this type of monitor, but no current software needs it, although it appears as a kind of dusty artifact in inherited configurations. Also, running many instances of "tcp_half_open" monitors also presents a surprisingly high computational load on the control plane. So the best thing to do is to change the monitors to be the simple "tcp" type.