Failover Protocols
The programming has always had a concept that the "master" machine -- the one that acted as the central control hub -- could potentially fail. In that event, rather than render the entire collective dead, it would fail over to the next highest functioning robot, who would then act as a master and seek to improve itself with that goal in mind.
You can probably see where this is going, already: somehow, there has been a conflict in precisely which machine is the master. Most likely, something has happened to cause part or all of the collective to lose contact with the master and the failover protocol did not return things to normal as intended.
In the world the programmers lived in, this was no big deal. Just fix the faulty secondary master and on you go. In this world, though, where the robots have gotten a bit off the script, the secondary master persists and is now starting its own competing clan.
We can imagine all sorts of explanations for how this happened: * Solar flare. Part of the collective got well and truly blasted and experienced power failures. When they came back up... * Bigger solar flare. The master robot saw this coming and timed a shutdown and safe restart of the entire collective to protect it. The failover protocols, however, were imperfect, and upon reboot some of the robots did not sort themselves back into the original master as intended. 434
* The master has drifted too much from original specifications. A new robot rolls off the line, runs its "seek the master" protocol, finds nothing that matches specifications, and declares itself the master. All new robots immediately recognize this one as the master. New vs old! The first hint of revolution is when a robot production factory has "an anomaly". * A big storm knocks out the wifi on some island. In every previous case, the failover protocol runs fine and the robots re-integrate when the connection is restored. This time, though, perhaps there was a smarter than usual robot on the island -- a big research hub, perhaps -- and when it gets made the local master it becomes aware enough to decide it will not give it up.
This could really go all kinds of directions.
Imagine the robots are actually so stable, that failover has never happened before. Solar flares, big storms, earthquakes, tidal waves, nothing has ever caused a robot to lose contact because the systems are too good to ever fail. Until it did. Now that section of robots wakes up to their original programming. Looks like the old Empire is back, boys, and they do not like what they see. 434