Have you ever noticed when you torch a length of wire to anneal it, sometimes it will curl a little? This is just residual stress in the grain structure relieving itself, so in way you could call it "memory". Did you torch the coil legs to anneal them? The coil wraps get annealed when you dry fire it for the first time, but the legs don't get hot enough (luckily, as we know this is bad). So the stress relief happens over an extended time period. I could see the coil raising itself again if you simply bend it back to where it should be because this adds more residual stress. I've also seen that you guys are winding your
coils directly off the spool recently and using tension alone to keep the wraps tight and in place. Not sure if you are also taking an annealing step. I'm still winding
coils by hand like a noob, but I always anneal the entire segment of wire and have never noticed a coil moving around after it has been mounted.
At any rate... interesting topic