Not sure when this happened, but the feature got broken:

https://user-images.githubusercontent.com/29597/130155150-18fbca13-42d7-4d7d-831e-8db4a9672d94.mp4

Using the up/down arrows to navigate the list works fine, but jumping to the next/previous component with a warning or error doesn't quite work correctly. (The scroll offset is wrong so the component is often not visible.)
const element = this.getElementByID(id);
    if (element === null || element.parentID === 0) {
      return null;
    }
    // Walk up the tree to the root.
    // Increment the index by one for each node we encounter,
    // and by the weight of all nodes to the left of the current one.
    // This should be a relatively fast way of determining the index of a node within the tree.
    let previousID = id;
    let currentID = element.parentID;
    let index = 0;
    while (true) {
      const current = ((this._idToElement.get(currentID): any): Element);
      const {children} = current;
      for (let i = 0; i < children.length; i++) {
        const childID = children[i];
        if (childID === previousID) {
          break;
        }
        const child = ((this._idToElement.get(childID): any): Element);
        index += child.isCollapsed ? 1 : child.weight;
      }
      if (current.parentID === 0) {
        
        break;
      }
      index++;
      previousID = current.id;
      currentID = current.parentID;
    }