I noticed the chain was a little slack (and the new S3X internals seem to have much less slop than the old, so I’m thinking “win!”), and the wheel has slipped a little – it’s cocked between the stays.
Loosen both nuts, straighten up the wheel, tighten the offside nut, tighten the drive-side nut, and CRACK! with a couple chrome flakes raining down.
Kind of bummed out my Sunday.