Server browser sporadically doesn't show LAN dedicated server

Version:  289257 OSX_STEAM

I think this started happening after one of the recent updates (never observed this issue before). Sporadically, a server running on the local network will not show up in the LAN section of the server browser - it does show up in the Online section, but that causes the client to connect through a punchthrough, resulting in obscene lag.

I don't recall this ever happening after a successful connection to the local server - the issue is most likely present from the first entering into the server lobby. Refreshing doesn't help.