You have surprised me ... I did not know that the Artistic had a stitch regulator available.
Unless by chance you are meaning the speed regulator?
If it is under a year, is there not warranty coverage to sort things out?
FYI ... the Artistic 18 is not made by Janome.
Janome contracted to market the Artistic line thru their dealers.
It is basically a Tin Lizzie re-branded and re-painted as Artistic.
So your answer may be in making inquiries about the Tin Lizzie.