MacBook Pro losing wifi connection when other devices work fine

I recently had my MacBook Pro in the Apple Store to repair a keyboard issue which resulted in the top case, battery and keyboard all being replaced because of a known issue.

I got my MacBook home and tried to connect to the wifi, which didn't work. Eventually I reset and reconfigured my router, reinstalled macOS and tried again. I am now able to connect to the wifi but the range is really bad. I can only connect within a metre or two of the router. If I take it into the other side of my bedroom or leave the room it loses connection.

My iPad, iPhone, and iMac are all able to connect easily from further away.

I have reserved a Genius Bar appointment, five days from now. I'm just looking for some tips and advice to solve it myself if possible, otherwise I'll let the geniuses figure it out, I guess.