Is there a bug in BorderManager 3.8 SP3 that won't accept Network
addresses (vs. Any Address or Host) when creating a Legacy filter
exception in iManager or am I doing something wrong?

Say I want to allow in NRM from all addresses beginning with 64.27.x.x. I
enter for the Source Address and for the Source
Subnet Mask. When I then go to hit Next it just stays on that screen, no
error. I assume it's failing some sort of validation test. If I choose Any
Address or Host (and enter a single IP) it works.