What went wrong
The plank did not fail. The floor ran out of room. Vinyl expands when it warms up and when it takes on moisture from underneath, and a floating floor needs a gap at every wall, jamb and cabinet to absorb that. Take the gap away and the expansion goes into the weakest joint, which lifts into a ridge and takes the tab with it.
You usually find it barefoot, when the light rakes across the floor: a ridge along a seam, a hollow click underfoot, and often a gap you had not noticed. One joint lost its slack and another was forced open.
The annoying part is that a buckled click plank does not go back. The locking tab is a thin profile of vinyl, and once it stretches it stays stretched. Stand on the ridge for a week and it lies flat while your foot is there, then lifts again when you move. Find the cause before you replace anything.
Why it happened
No room at the edges. A floating vinyl floor needs a gap at every fixed object: skirting, jambs, pipe collars, toe-kicks. Vinyl wants about 1/4 in (6 mm), though the carton wins. Butted to the wall, a warm afternoon has nowhere to push except the nearest seam, the same no expansion gap mistake that leaves laminate peaking at the seams.
Heat. Vinyl softens and expands as it warms. A dark plank in direct sun gets far hotter than the room, and a radiator does the same. A floor with a gap copes; a tight one lifts.
Water underneath. A slab with no vapour barrier, a slow leak, a spill that sat, a wet mop used weekly. Vinyl does not swell like laminate, but water lifts the adhesive on a glue-down floor and cups a plank at the edges. A tide mark is the tell.
Something under the plank. A crumb, a staple, a screw head, a lump of dried adhesive or a high spot. The plank bridges the lump, rocks when stepped on, and the joint above opens. People skip this cause because checking means lifting the plank.
Click and glue-down fail differently. A click floor can sometimes be saved by restoring the perimeter gap and letting it settle. A glue-down floor is stuck, so a lift usually means the adhesive has let go.
When to stop and call someone
Stop if several planks are buckled, if the ridge returns within days of cutting the gap, or if the floor runs under a cabinet or island with no gap. Stop if the subfloor is wet, the slab has no vapour barrier, or planks are lifting in another room. A floor that buckles twice is telling you the cause was missed.