Yes. There's a problem with the connection between the lighting cluster and the vehicle earth. It might be a loose connection or broken wire or a cracked copper track if the lighting cluster is based on a printed circuit board.
You'll need to do a bit of working out and thinking.
Actually, it might be a common problem. If that's the case it will probably be mentioned in some of the dedicated Peugeot forums - easy enough to find. Maybe a search based on "206 indicators" will throw something up.
Dfyd, November 2021
