Structure Block blank seed is not actually random

Hello, I've got a little bug for you.

I'm trying to create a redstone contraption utilizing structure blocks but I found that using a low integer with a blank seed while initially will place blocks at random, it will only work one time, even if I copy the structure block and place it somewhere else it will place the blocks in the same pattern as if there were numbers in the "seed" field. If I attempt to erase the numbers in the "seed" they'll come back an load.

Thanks