Janome 6600p issue
I am having an issue with the upper thread tension in my 6600p "drifting" on its own while I'm sewing. I noticed it a few months ago while I was quilting with my accufeed foot. I'll have it set to 5, and then look up and it's on 3! When I started really paying attention, I realized that it was doing it after I would finish a row, move the quilt, and put the foot back down. And then, my foot lift lever fell off. The screw had backed out. I went to put it back in, and realized the screw goes under most of the foot mechanism so I took it to the shop and told him to figure it out. He said he had never seen the lift lever just fall out like that. He took it apart, cleaned the heck out of it, and put it back together for me. He told me he soaked the tensioner in cleaner and oiled it back up and I should be good. I've had it back for a couple of weeks and it's been fine, until last night when I went to quilt with me accufeed food - it's "drifting" the tension again (from 5 to 3) just like before. Any ideas?!