Macbook Pro only connects to wifi in one room of house

My MacBook pro retina display only connects to the wifi in one room of my house. There isn't a problem with the BT router because all my other apple devices connect to the wifi in all parts of the house with no issue. So I believe there is a problem with the macbooks ability to connect to the wifi. It obviously can connect as it does so in one room of the house. However, it is extremely annoying that it only connects in one room and is restricting my use of the MacBook. Unfortunately, booking an appointment with a genius is pretty much impossible these days as appointments are like gold dust. I have tried going onto the wifi settings and forgetting the network and then trying to connect it again but this doesn't work.

Would really appreciate being pointed in the right direction.

Thanks