While working on making connections on 168 (8/10) I noticed some unconnected tracing with no signal under it. I thought, “tsk, sloppy tracing.” Then I noticed the line was very similar to one about 1/2" away. Apparently after I traced, something shifted; then I came back later and traced the same thing over again. The lines are not identical so I know they were traced separately. I found several of these, always unconnected; I don’t know for sure, but I suspect the shifting all happened at the same time rather than separately as I have not found new examples the last couple of days. No idea what prompted it.