I've installed alot of laminate flooring, I remember when they first came out and you had to glue the pieces together with the manufacturers' special glue plus their own residue cleaner. They were more expensive than alot of hardwood floors back then.
Now that it's all clicked together without any glue you get weaker joints.The short edge of the flooring plank is vulnerable to gapping. Even though you leave the appropriate gap around the perimeter, placing heavy objects on the floor, ie, furniture, file cabinets (the worst for laminates), essentially renders the planks beneath them stationary and inflexible. If two heavy objects are on opposite sides of the room and contraction/expansion occurs the planks between the 2 heavy objects buckle or separate. So you get a gap or bubble somewhere in the middle.
I warn clients before I install laminates about this potential problem. It happens with alot of laminates, Pergo, Wilson Art.