Help with an automation to set volume on an echo show

I’m trying to reset the volume using the new previous_volume attribute on a media player. This seems to work in the template checker but it won’t compile and load in an automation. HELP!.. please…

action: media_player.volume_set
target:
  entity_id: media_player.bedroom_south_show
data:
  volume_level:
  value_template: {{states.media_player.bedroom_south_show.attributes.previous_volume|float*10}}

What am I doing wrong?