Poor connection WN3100RPv2

Hello everyone, so it has been a while trying to fix my netgear extender, I called orange in France to tell them the issue but they told me nothing we can do. Therefore, I restored it, in the meanwhile, the extender is working but with a very weak connection even on the phone the WIFI bar is full. I checked the internet speed and it is fine and I am pretty sure that I am connected to network EXT. All the arrows are green, it means everything is good. The extender is placed 2 meters far from my room and about 7 to 10 meters far from the router. Please I need help to find the problem