My initial guess (having had similar layer shifts in the past) is that one of those skinny ‘Y’ vertical pieces with angled overhangs simply curled up a little too much (shrinking warpage) and eventually the nozzle took a path where it made contact with the raised edge and cause the motor/belt to slip until it continued in the new position.
Ways to prevent include much higher cooling for those curling points (super slow high fan), or enclosure of the entire unit to mitigate warping.
Sorry for late response, hope it helps or you solved it.