It is interesting that your threader works in embroidery mode but not when you are sewing. Do you use different needles for sewing and embroidery? I discovered my threader works when I use Janome needles but not when I use Schmetz needles.
Judi
[Moderator Note] Embroidery needles have a larger eye, so there is more room for the hook go to through. It the threader has been adjusted to a size 14 (Janome standard procedure), the eye may not be centered for the hook on a size 11.