Appears to be working in Firefox but at least Chrome & Safari are broken. Should be a really recent regression so very few possible changes to blame...

Easiest repo: the todo list on our homepage.

}
    if (styleUpdates) {
      CSSPropertyOperations.setValueForStyles(
        getNode(this),
        styleUpdates,
        this
      );
    }
  },
  /**
   * Reconciles the children with the various properties that affect the
   * children content.
   *
   * @param {object} lastProps
   * @param {object} nextProps
   * @param {ReactReconcileTransaction} transaction
   * @param {object} context
   */
  _updateDOMChildren: function(lastProps, nextProps, transaction, context) {
    var lastContent =
      CONTENT_TYPES[typeof lastProps.children] ? lastProps.children : null;
    var nextContent =
      CONTENT_TYPES[typeof nextProps.children] ? nextProps.children : null;
    var lastHtml =
      lastProps.dangerouslySetInnerHTML &&
      lastProps.dangerouslySetInnerHTML.__html;
    var nextHtml =
      nextProps.dangerouslySetInnerHTML &&
      nextProps.dangerouslySetInnerHTML.__html;