The recent cold snap was what popped it loose, or better said the cold front caused the wood to move.
I don't buy that.I know Florida is along ways from Maine, but wood movement is wood movement,and whether it was a cold morning with a heater running, or a hot, humid day in the summer after a cool night, temperature change is going to happen.
The companies that cater to homeowners know this and do extensive testing on the proper way to get the product to stay in place despite these changes. I think some short cuts were taken, with the gap between the wall and the flooring being the biggest error by the sounds.
The wood expanded, probably from wicking moisture up from the concrete slab, had no where to go, and buckled. I have seen this before, but this was in a caboose, and the darn thing pounded down the rails at 60 mph, so its hard to blame the flooring material.
I'm afraid a total restart is in order here. You could do some goofy things like adding a screw here and there, but ultimately you will just end up chasing the pop ups all over the floor. Better to start over and do it exactly as the instructions say,and not the salesman.