Bad batch of worms, or bad food choice?

Normally I buy a bin of red wrigglers(my axolotl likes them blanched and they're the perfect size right now) and keep them in the fridge in the bin they came in, which is full of dirt. I feed them tea bags and paper bits usually, and then when I run out of worms I give the dirt(which is always full of worm "eggs", so I assume the worms did well before my axie ate them all) to a friend who gardens a lot.

But my newest batch of worms has gone all wrong. When I got them, I wasn't quite done with my previous batch, so I didn't look at them when I first got them. I threw in some clipped leaves from my edamame plants for them to eat, since I didn't have any tea that day. Two days later, it was time to start using the new worms. But there was a LOT of dead ones, and most of the living ones had huge swollen sections! So I fed my axolotl pellets instead.

So I'm wondering what went wrong here. Are edamame leaves dangerous for worms to eat, or did I just get a bad batch of worms? What kinds of things cause them to swell up(mostly near the heart area, but sometimes in other areas)? I haven't thrown them out yet...are they safe for my axolotl to eat? I tried blanching one experimentally and the heart area(which was very swollen) exploded. I didn't feed any to the axolotl.

I think you either got a bad batch of worms, or else the edamame became more rotten than they could tolerate. In comparison, tea bags and paper bits don't rot as nastily.

Red wigglers are considered a pest - an invasive species in some places. I would recommend trashing leftover worms and eggs, not releasing them to the outdoors. If you do a web search for "invasive compost worms", you'll find lots of info.