The Anti Personnel Missile of Titan Launcher Compact does not support the TOP fire mode, this Missile able attack only in DIRECT Fire Mode.
But if player, currently in TOP fire mode will change missile from AT-Missile, to AP-Missile, then in the player UI (Icon of fire mode in the screen corner) the Top fire mode will not be changed automatically to the corresponding direct mode. Player UI must not cheat Player - it should show only currently supported fire mode.
This was work before update 2.08, most likely broken by recent updates.