Hassio 67.1 stopped themes from loading?

hi,

is anyone else experiencing theming issues with the 67.1 hassio:

this worked beautifully before, but now the theme isnt loading any longer, while the other 2 (icon and state display) still work fine:

sensor.huidig_tarief:
  templates:
    icon: >
      if (state === '1') return 'mdi:numeric-1-box-multiple-outline';
      else if (state === '2') return 'mdi:numeric-2-box-multiple-outline';
      else return 'mdi:fire';
    theme: >
      if (state === '1') return 'green'; else return 'orange';
    _stateDisplay: >
       if (state === '1') return 'Laag'; else return 'Hoog';