No comander in start game

Could you provide more information? Tell us how you got that. Were you playing a single player mission? Custom singleplayer games in your own room? Multiplayer? Were you a spectator?

Probably checked "Hide Trainer Comms" by accident.

Press F10. There's a Search button at the bottom - click that, type "trainer", press Enter. This should find a checkbox "Hide Trainer Comms" - uncheck that.

I don't understand how this could be clicked accidentally. There is no such checkbox in the commander selection window so new players would have to navigate through the menu and somehow find it. Is this really what happened?

Perhaps the checkbox should only be displayed if "Show Advanced Settings" is enabled? Or perhaps trainer comms should be displayed for players without any custom commanders regardless of whether "Hide Trainer Comms" is toggled on?