Despawning Issues

[The User COOKIE]

So, I'm having an issue with a forge map I am trying to build. I am utilizing the pressure plate mechanic, so that when you step on the plate, a container large comes out to block your path, and another one drops to open up a new path. But anyhow, the crates keep despawning and respawning again. I have tried to set the min count to 2, but that did not work. The best I can get it is to set the respawn time to 1, but that doesn't really help. Would putting a grav lift that is constantly pushing the boxes stop them from despawning? Any suggestions would be greatly appreciated. Thanks in advance!