Adding zoom statement to my sprites makes them forget the custom default anchors I set for them.

I have set up a custom default transform for my sprites in my gui file to define my sprites anchor as x .5 and y 1.0 like its shown here:

transform _sprite_default:
    xanchor .5 yanchor 1.0 xpos .5 ypos 1.0


define config.default_transform = _sprite_default

But when I put the zoom property on my sprites, they default to showing in the top left corner of the screen with their anchors in the top left corners of their images as is default for sprites in renpy, effectively forgetting the new default I set in my gui file.

Why is it doing this?