Blocks Field not letting when work

Hello
When i use the new blocks field in 3.5 i’m not able to use “when:” to hide it under certain conditions.
Any other field type works with the same settings.

displaytype:
  type: select
  label: Display Type
  options:
    vimeo: Vimeo
    blocks: Blocks
  required: true
  width: 1/2

blocks:
  when: 
    displaytype: blocks 
  type: blocks
  fieldsets:
    etc

This should be fixed in 3.5.1, released today.

Ha great timing.