When using Flame Life and setting it to 0 in 19.5 you still get a flame. So there is no way to cut back a flame currently in 19.5, is this bug just in my build?

I'm on 19.5.425

if there is still flame then you are probably sourcing them "every frame" and they immediatly live for just this one frame before another is sourced in the next frame which is also immediately killed.

if you want to really test test, make sure to source "flame" for just one frame in SOPs before the sim and check how many frames that "single frame emission" will live on.

also maybe provide a hip file?