Vaadin system errors

Flow
1

Is anyone else getting a lot of Vaadin system errors in version 14.1.18? My latest one appears to be in a client-xxx-cache-js file. The TypeError message is _expandedButton is null. Before the client-xxx-cache.js files, the last file is the one shown below with the last line starting the chain of about 9 calls in the client-xxx-cache file. Is there anything I can do to debug/fix this?

/**

  • @event vaadin-overlay-open
  • fired after the vaadin-overlay is opened.
    */
    _openedChanged(opened, wasOpened) {
    if (!this._instance) {
    this._ensureTemplatized();
    }
    if (opened) {
    // Store focused node.
    this.__restoreFocusNode = this._getActiveElement();
    this._animatedOpening();
    afterNextRender(this, () => {
    if (this.focusTrap && !this.contains(document._activeElement || document.activeElement)) {
    this._cycleTab(0, 0);
    }
    const evt = new CustomEvent(‘vaadin-overlay-open’, {bubbles: true});
    this.dispatchEvent(evt);