It was assumed the problem with slimes not splitting was attributed to the mob stacker plugin. After killing several slimes since the plugins went down, slimes still do not split. So we can rule that out as the cause of the problem. Yes?
The staff team is already aware of the bug. It has been confirmed, however, that naturally spawned Slimes DO split. It is the spawner ones that do not. They'd most likely need solid proof that the mob stacker plugin is NOT a cause by doing some testing.
Yeah, I did a ton of testing with Aeroxas' area and found that only the naturally spawned ones would. We're looking into why currently.
Marsh and I also tested this around the Swamp biomes. She recorded and sent the video to you guys, I believe.