Can't connect a 2012 Apple MacBook Pro to Plusnet Wi-Fi Network with Plusnet Hub 2 Router

[#1]

My iPhone, newer MacBook Pro and other products all connect to wi-fi using the wi-fi password, but, irritatingly, not one older MacBook Pro. I have tested with Apple Support, who have connected the MacBook to my phone's network ! It just doesn't seem to be able to connect to the Plusnet wi-fi.

Any help much appreciated.

[#2]

Welcome to the community

On the Hub Two look at Advanced Settings >Wireless; here you will find "Wireless Mode" setting, it might worth trying on Mode 2

This mode allows you to tune your wireless features to give you the best performance with all your wireless devices.
Your Plusnet Hub is automatically set to Mode 1

Mode 1: Gives you the fullest featured wireless, maximising throughput and range.

Mode 2: Some devices can sometimes struggle to use the latest Wireless features, if you have any devices that can't get a good wireless connection, try using this mode. Selecting this mode may reduce the wireless range and throughput but improve connectivity.

Mode 3: Change to this mode if your wireless devices don't perform well using mode 1 or 2. Selecting this mode will reduce the latest features as well as wireless range and throughput compared to Mode 1 and 2. This will allow for the broadest range of devices to operate on the wireless.
The features that are reduced include: power saving procedures, traffic aggregation methods and Multiple Concurrent data streams.

HTH

[#3]

Many thanks for your prompt response and helpful suggestion.

I have switched to Mode 2, as suggested, waited, then powered on the MacBook again, but am still unable to connect to my Plusnet home wifi network. 

[#4]

What was your previous router?

As matter if interest did you try Mode 3; maybe for a test try turning off the 5GHz signal to see if that helps. Both options would really be just for testing.

The wireless adapter maybe having issues with a 2.4 and 5Ghz wireless signal using the same network name (SSID), when you tested using a hotspot you would have only had one of the bands.

Maybe buying a more up to date USB wireless dongle might the best solution.

Edit: on some network devices it is possible to fix the wireless signal used, see if you can force the MacBook just to use 2.4GHz