I had a similar experience years ago, also with a cheapie version. It came out of the bag as neatly separated squares of aluminized "chaff" that I had to chase around the whole darned campsite.

The genuine "Space" brand space blankets, gold on one side and silver on the other, seem to hold up reasonably well in storage. Good items for first aid kits.

I'm looking forward to trying the new HeatSheets. I bought two but never got around to opening them.