iOS - is the subtract, divide or distance shader math broken?

I’m at a loss. I don’t know know what else to do. There’s clearly a precision problem coming from somewhere, I just don’t know where exactly.

I tried replacing all the nodes I suspected to be an issue and I just can’t get this to work. What I’m trying to do here is so basic, I refuse to believe that this a limitation of iOS or mobile in general. I’m sure there’s a problem with how the shaders are being built for iOS.