It may be the laptop you are using - or its built in wifi connection. You might also try updating the drivers. We were at one campground where my wife's laptop would not connect at all but I was able to connect with both a tablet and a laptop with no problem. We bought her a USB wifi adapter and plugged that in with the laptop's own wifi turned off and she was able to connect then at that campgound. This has happened in a few campgrounds we have been in. There was one where my tablet would connect but the laptop wouldn't.
It may not be how strong the signal the wifi is putting out but the type of signal it is putting out. My laptop and tablet are newer than my wife's laptop that would not connect.