Okay so I found a weird solution that is “technically” a solution.
I found out that for some reason, the only thing that doesn’t render properly on build is text because it works on images. So I tried using images instead of text but it didn’t work at the start.
But then, I added CreateWidget of the player indicator into the gamemode’s beginplay and for some reason it worked. (This can also be done in the level blueprint).
It doesn’t necessarily solve the text nto showing issue but it did solve my problem of displaying the player indicator in the build.