Thanks all for your interest.
I received the machine back from Janome yesterday evening, and did a quick 'thread'. It was fine and felt completely different to the first time I tried it.
In the stupid way of things, I now have 5 days of medical appointments & family commitments, so won't get to use it properly until after the weekend!
However, it now feels 'right' so am a lot happier, but quite unable to help anyone else with their threading issues! Janome's collection & delivery were very efficient.
Everything else about the machine is excellent. I did a 'trial piece' - the Mallow top from
Tauko #3. This patches woven scraps and uses them to bind & decorate a knit top. So I used lots of different stitches. Scraps from previous projects, and a knit from a 'lucky dip' box; but I have ended up with a very decent top, so am pleased