I've had a couple of this style of plastic clip crack. Wrapping it in thread and then applying super glue seems to work pretty well. I also tried wrapping with fishing line, but it came undone pretty quickly. Just wanted to share the tip! Now if only I had a fix for when the prongs on the other half break off.
Why are they breaking though
Looks like brittle bottom of the barrel plastic to me.
In this case combined with accidental side pressure and cold weather.