I installed a shaw longstrip snap together in a long foyer down along hall to the right a kit/nook/around a bar straight a head pretty cut up plenty of expand room but it wood creek alittle when you walk on it. I heard another guy said he had one expland omost a inch in 12 feet yall ever a problem like that

Assuming your substrate was prepped correctly, the only thing I can offer is that by having alot of narrow runs, turns and wrapping around, the floor may have lost some of it's overall integrity.

Glue-less joints are gaining a reputation for similar problems.