This is a silly Android bug, but your message should still be sent to the player you have selected. As far as I know, it's just a visual bug. Annoying, but it has little effect on what's going on in the game itself.
"This city of Osgiliath has been reclaimed...
FOR GONDOR! FOR GONDOR! FOR GONDOORRRRRR!"
-Boromir, Son of Denethor I Osgiliath, Realm of Gondor Third Age, year 2475