The ingame MOTD is a minecraft function, and not a MineOS function, so this looks like a Minecraft bug. It may be related to this : https://bugs.mojang.com/browse/MC-2215?jql=text%20~%20"MOTD"
IF the MOTD works correctly for WAN, but not LAN games, this seems strange. Do you mean the autodetected LAN-world list? Do the MOTD show up correctly if you add the server manually (with IP-address) using the “Add server” button?
If manually added servers show corerctly while the auto-detected servers show up wrong the bug seems to be in Minecrafts routine for scanning for and autodiscovering and displaying LAN worlds. In this case there is nothing MineOS can do about this.
If the server displays MOTD shows wrong for both, it is most likely the formatting bug from above. It may be that this could be programatically fixed in MineOS, but fixing Minecraft bugs is really outside MineOS’s scope.
Remember that MineOS is only a Web User Interface to manage Minecraft servers. Anything that is inside the game is a minecraft bug, and outside MineOS’s control.