Spawn chunks not loading!

We’ve been playing on my own Minecraft server with some friends for about two weeks now, it is always on 24/7 on dedicated hardware. I’ve made a couple of farms in the spawn chunks, one sugar cane farm and a villager breeder.

The problem is both stop working as soon as I leave the spawn chunks, even after making a timer that drops an item into the nether like every 5 seconds, we’ve also tried a plugin that keeps chunks loaded, but that didn’t work.

Are there any other options or settings in Minecraft server that can be used to force loading spawn chunks? I’m kinda out of ideas…