[MOBILE] Green squares bug


I am building a new game with the sample simple vehicule project in blueprints, when i launch on mobile I am getting these weird green squares on my screen, I have made 2 games already for mobile so far and I have never encountered this issue, so I would like to know how to fix this.

This happens when I open a new map.
This does not happen on the main menu map.

Screenshot below, many thanks.