Web content and google sheets - instructions don't work out

I've been trying to update a dashboard to include the new Web Content widget since I find managing some data and charts in Google Sheets far easier than in Smartsheet especially when collaborating on the data / file.



I've followed along with the instructions for the Google chart I've created. Publish > Embed > and copy that code.



The result when pasted into the Web Content Widget is just a blank widget. I notice the Embed code includes the <iframe> </iframe> links, and the widget removes those once you hit "OK" in the "Select URL" pop up screen. The result is simply the same code which would have been provided by the "Link" option within Publish on Google Sheets.



I've tested my generated publish code... it is indeed published to the web as I and others can see it without issue. I've included a set of screenshots to show the process and result, file names should be enough to explain what each is showing.



Would appreciate any help as I'm either overlooking something, or stared at it so many times I just can't see the simple mistake at this point.



Thank you.