A lot of people have problems and some usb adapters work and others refuse to.
Some of them have problems with long names and passwords or those that contain special characters.
If you can suffer more testing… and to rule the above out
I’d make a note of the SSID and password from your router normally on 192.168.1.1 admin/admin, something like ‘TALKTALK-12345 ABCDEFG8’
and change this to something simple, all lowercase such as ‘talktalk talk1234’, reboot the router, wait a couple of minutes and try again with the Humax
Obviously all your other wifi stuff will have problems for the duration, but this is just a test. If you can get it to work with a simple SSID and password then you know what the problem was and choose a more suitable SSID and password.
If it doesn’t work then it looks like you’ve picked up an adapter that doesn’t work.
I’m assuming the usb adapter is fairly close to the router i.e. the signal’s not being blocked, sometimes they’ll come with a small usb extension lead so they can be better placed for reception.