Geometry Nodes tutorial: different results from original /file attached

I’m following this tutorial:
https://youtu.be/g5Ov4n0LRm8

But getting different results from the OP, specifically my geometry never flattens out like his. Unfortunately he seems to have removed the previous, more basic version of this tute (at least I can’t find it) and I’m rubbish at GNs, so at a loss to where the error crept in.

Also, this OP seems to be re-using variables/attributes in his network (like the old BASIC " x=x+1"), which I find confusing. Is it correct to think that “frames” is getting assigned different values at different points in the network?

So, what needs to be changed to get a disk that flattens out at some point in the animation?

Thanks.

LoopingRings-NoBueno.blend (989.2 KB)