Tile Stamp Not Randomizing

I am trying to use the Tile Stamp as intended to create a random pattern between 5-10 2 tile high trees, but no matter how many variants I add, or what probability I put, the tool is only using one of the variants (and at that typically only the stamp image). It worked for a few minutes the first time I used it, so I am not sure what I did wrong. I thank you in advance for your time and wisdom!

Select the first variation of tree and click “create stamp”. After that select another variation of tree and add this with the “+” to the stamp. You should then see a number next to the stamp name. Open the stamp with the arrow on the left and you can see the probability of each variation. Change probability or add more variations to this stamp.

But don’t use the Random Feature to randomize stamps if you use pattern with more than 1 tile.

Thank you for the response! I am able to create just like you described, but the variations are not popping up. I’m including an animated gif to demonstrate, maybe someone will notice what I’m doing wrong.