My understanding is that it relates to the flood routing in meshtastic. I haven't heard a real-world failure example, but another comment on this post mentioned defcon being a case (I don't know anything about that).

I did find this assessment:

https://www.disk91.com/2024/technology/lora/critical-analysi...

And here is Meshtastics explanation of the rationale behind 'managed flood routing':

https://meshtastic.org/blog/why-meshtastic-uses-managed-floo...

I think I first heard about the differences from Andy Kirby, one of the MeshCore creators: https://www.youtube.com/watch?v=fNWf0Mh2fJw