This is probably a manual override of the databases requirement:
WNVC 24 Fairfax, VA uses 30.1 through 30.5 as virtual channels (ex 56 analog)
WNVT 30 Goldvein, VA uses 30.6 through 30.10 as virtual channels (ex 53 analog)
This pair settled on 30 because WNVT never simulcast analog and digital. It's a pretty cool effect when both channels are received. Station IDs are correct on each subchannel using a grey bar across the top of the screen with white characters.