Error Message when rendering Lightning Web Component in Salesforce

I have recently been working on embedding power bi into a salesforce LWC, as outlined here: https://github.com/PowerBiDevCamp/SalesforceAppOwnsDataEmbedding. Pretty cool stuff, but the particular use case may be beside the point. I am having some sort of rendering issues with the lightning web component. Here it is:

import { LightningElement, api, wire } from 'lwc';
import getEmbeddingDataForReport from '@salesforce/apex/PowerBiEmbedManager.getEmbeddingDataForReport';
import powerbijs from '@salesforce/resourceUrl/powerbijs';
import { loadScript } from 'lightning/platformResourceLoader';

export default class PowerBiReport extends LightningElement {
  @api WorkspaceId = '';
  @api ReportId = '';
  @api recordId;
   
  @wire(getEmbeddingDataForReport,{
    WorkspaceId: "$WorkspaceId",
    ReportId: "$ReportId"
  }) report;
    renderedCallback() {
      Promise.all([ loadScript(this, powerbijs ) ]).then(() => {
        if(this.report.data){
              if(this.report.data.embedUrl && this.report.data.embedToken){
                const reportContainer = this.template.querySelector('[data-id="embed-container"');
                const reportId = this.report.data.reportId;

                const embedUrl = this.report.data.embedUrl;
                const token = this.report.data.embedToken;

                var visualConfig = {
                  accessToken: token,
                  embedUrl: embedUrl,
                  id: reportId,
                  pageName: 'ReportSection',
                  tokenType: 1,
                  type: 'visual',
                  visualName: '1837fab00804802016c6',
                  settings: {
                    panes: {
                      filters: { expanded: false, visible: true },
                      pageNavigation: { visible: false}
                    }
                  }
                }
                // Embed the report and display it within the div container.
                var report = powerbi.embed(reportContainer, visualConfig); 
              }
              else {
                console.log('no embedUrl or embedToken');
              }
                
              }
              else{
                  console.log('no report.data yet');
              }
        });
    }
}

Now this works fine and as intended. The getEmbeddingDataForReport returns all the necessary data (embed url, token, etc...), and I have the chart embedding and showing up (mostly) properly. I have the lightning web component on a lightning record page. But here's the problem. Occasionally when the page loads, I get an error message:

After occasionally getting this error pop-up, I did some digging and noticed that I ALWAYS get it if I click on 'Edit Page' to pull up the lightning page where the LWC is embedded. When opening the console, I see this error message duplicated about 4 or 5 times: "Uncaught (in promise) DOMException: Failed to execute 'postMessage' on 'Window': # could not be cloned."

After logging at some random places, I noticed that I do not get this error if I comment out the line where powerbi.embed uses the configurations and selected html id to embed the actual report. So, there is either something wrong with this line:

var report = powerbi.embed(reportContainer, visualConfig);

or this line:

const reportContainer = this.template.querySelector('[data-id="embed-container"');

I am pretty stumped on this. I don't have the slightest idea why this could be happening. I read a couple things online that indicated this error often relates to embedding a LWC in a context that doesn't support LWCs and that the solution would be to wrap the LWC in an Aura component; however, I don't believe that applies here because the LWC is embedded in a lightning record page, which clearly supports LWCs. So, somethings is going on under the hood here relating to one of those two lines I pointed out...any ideas what is happening here? Please help!!