Unity game starts lagging and then freezes

So I've made a machine learning simulation using the NEAT algorithm and I can't figure out why after about 5 generations the game starts lagging and then freezes with high CPU usage.

Could it be something accumulating? I've cleared any lists after I've used them as well as deleting any unnecessary gameobjects that I don't need but it's always after 4 or 5 generations it starts lagging.

I have no idea what is causing it or any idea how to identify and fix the issue.

Does anyone know anyway I could go about solving this?

Here's a video showing the issue:

I understand there's not too much to go on but I don't really know why it's lagging this badly.

If needed I can provide a link to download the project.

 

Im new at this, but maybe try to destroy clones after a certain amount of time?
Hopefully that fixes your issue

Example: Destroy(GameObject.Find("the name of the gameobject(Clone)"), 5);