Hi Tom

You may have this problem sorted by now, but I recently acquired the
Brother KA-8310 and had problems with it initially.

I solved it in two ways. First I renewed the retaining bar, and secondly,
gently pulling downwards on the knitting as you link enables the knitting
to come off the needle.

In my manual it also says to knit the final row of your knitting at a
higher tension than usual IE

Medium Yarn - 10
Fine - Very Fine 9-10

Hope this helps.