Was a bit shocked to find my brand new Silva 360 Jet is not too good: https://youtu.be/hb9Oqg4Zqa4
Where in the (magnetic) world are you Duncan? One might expect compasses for the various zones to come from different manufacturing batches.
Down under, the current batch of Silva jet compasses seem to have a different problem, the needle departs from north if its not absolutely level, but it doesn't stick as yours has. Reputable sellers will replace or refund of course.
That's a shocker for a new compass.
Send it back and get one of these instead... www.str8compass.com