3DPrinting

So... just to clarify, you've ruled out loose belts?

working backwards-the first thing to check is your belt. Assuming the belt is fine, how is your accel and jerk setting? Id assume those are okay-ish out of the box, but it's worth a look. a fast move coupled with a slightly too-loose (or too-tight...) belt could hurt things.

From there, I'd check to see if the nozzle was dragging/catching on anything. (look at the failed print part. you might see nozzle marks. or see where it started.) depending on what material you're printing on, warping could raise the part up high enough to drag the nozzle, causing slipage in the belt. if it got stuck because the part was obstructing the nozzle, then it'd resume when it got high enough to clear it, but with having lost the x position.

filament unspooling poorly- regardless of what causes it to do so- that would likely have stripped out the filament at the extruder's hobbed bolt. you can test that by holding the filament from unwinding while it tries to print some. You might also be able to see filament powder/chewed bits around your extruder.

Edit to add: is this a Bowden rig? A Bowden tube maintains the length (and length of filament inside it,) without regard for the x position, so it would be difficult to see how a stuck reel could cause a layer shift,

as a side note, you might be able salvage the print by measuring to where the height to where you lost the print, splitting the part at that height and starting a second print there. then, glue the new part on with some coarse sanding and CA glue.

If I had to guess I’d say the nozzle caught on something. Id look for a spot where a layer was curling upward (like a tough or unsupported overhang).

1/2" is a lot... is it possible the print head made contact with the part on an x move and shifted the entire build plate? That happened to me recently on my ender 3 v2, knocked the entire glass plate on the floor and left me with mom's spaghetti

Filament spool issues won't cause layer shifts in bowden printers, it's a risk only with direct drive.
At the root of it, there are only two possible causes for a layer shift like this - either the motor skipped steps or the belt slipped on the drive pulley, and judging by this gap, my guess would be the belt slipping because it's not tensioned properly - and even if it is, you should seat that belt correctly anyway.

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.

Just to add an additional thing to check: are you sure the model maintained its position on the layer the entire time, right?

If it is the spool loosening due to carriage movement then using a Bowden tube as an umbilical, and mounting it in a fixed position in relation to the spool should solve it.

I was having an issue like this last week, and surprisingly, I was able to finish my print by using a new slicer. I was all prepared to go buy a new board for my ender3v2. I had even put a bigger fan on the board to try more cooling but still kept getting it on this large print. I sliced it in superslicer instead of cura, and it printed. Unless you're just eager to spend money and replace parts, not necessarily a bad thing, I would take a stab at a different slicer first.