Could it be that it is not the hud but the GameMode that is not getting packaged? In the log after the level has been loaded it should print out which GameMode has been spawned. If it’s not yours you have some ways of adding a GameMode to a level, either by hand adding a reference into the WorldSettings of the level or setting up a lookup that will match the actual level name. The later is the most flexible way of making sure your mode is cooked (give me a sec and I’ll post an example case).
let’s say you have a deathatch game mode that needs to be set for every DeathMatch map in your game, so you would add it by hand to each map or you could tell the engine to add it automatically if the map name matches. To do that just go into your DefaultGame.ini file and add the following values (of course use the reference for your own game mode and prefixes).
As you can see we just created a link between a level prefix and a game mode, we also added some aliases to be able to refer to the mode easily. The aliases are used to change a game mode when you travel, so instead of using ‘?game=/Game/Blueprints/Modes/MyDeathMatchGameModeBP.MyDeathMatchGameModeBP_C’ you can now use ‘?game=DM’.