GPN01
A little more understanding of the international NOTAM system will help you.
You clearly understand that the way to get a briefing for an area is to choose to a/d that straddle your area of interest and set up a NRB between them with a route width that defines a box Xnm either side of the track. (quite why you want a box 120nm wide and only 22 nm long is a bit of a mystery)
In your case Cambridge to Southampton is 94.5nm. NOTAM B0404/06 regarding Solent Radar's hours of operation has a radius of operation of 50nm which means that it extends some 15.5nm into the box you defined. That is why it is included.
Is the substance of your complaint
1. That there was something wrong with what you were given
or
2. That you don't understand how it works?
I recommend the
website user guide.
If you still have problems suggest you call the Duty Officer and ask for Dave Smith. He's a gliding instructor who works there and will certainly be able to help.
Mike