Material animation

I have a candle flame that I want to fade out a tad before it snuffs out on it’s own accord. I am using particles with halos on. I added a keyframe for alpha and then took the alpha all the way down some frames later, and then added another key frame. Moving through the frames with arrows keys (or alt a) the slider moves down and the alpha reduces. But when I render a preview frame, the alpha jumps all the way back up to it’s original position and it renders with that original alpha value. Then moving the arrow keys it jumps back down to zero. What have I done wrong?

LGM

https://blenderartists.org/forum/viewtopic.php?t=4021

Oh! Thanks.

LGM