A reference from HUD to Pawn question

Hello guys, i’m currently having a weird problem and maybe someone could explain me.
So i have a HUD where i generate some interface with math. Also i have a camera pawn class with controls in it. Then i’m also have a character class i’m using as character in RTS.
I spawn this character in it, also spawning the camera class and from HUD i’m using a reference to Camera class to get some variables inside this class and control the movement of camera according to the HUD.
So when if i assign HUD and Pawn camera in game mode it works ok.
But if for example i want to avoid assigning camera pawn in it it gives a reference error from HUD part even tho the camera pawn been created on the scene already.
Can somebody explain me how it works, is there any way to reference from HUD to Pawn without assigning it, or is a HUD only works with assigned objects inside game mode?
Thank you.