3.5.1 Theme breaks Drupal Webform Conditional logic

[norsargsyan]

Steps to reproduce:
Create a webform with conditional logic, to make a visible element when the radio element value is "something"

visible:
  ':input[name="type_of_comment"]':
    value: content_of_the_following_region

Browser console:

Uncaught SyntaxError: Expected property name or '}' in JSON at position 1
    at JSON.parse (<anonymous>)
    at _loop (states.js?v=9.5.10:35:27)
    at Object.attach (states.js?v=9.5.10:45:9)
    at drupal.js?v=9.5.10:24:24
    at Array.forEach (<anonymous>)
    at Drupal.attachBehaviors (drupal.js?v=9.5.10:21:34)
    at drupal.init.js?v=9.5.10:24:12
    at HTMLDocument.listener (drupal.init.js?v=9.5.10:14:7)