Found another solution:Played with it some more and noticed that all my thumbnail images were being set to 59 by 59 for their intrinsic values and there was a srcset that had a typo.  when the srcset specifies the media width, it couldn't look past i...

Just flagging you to my response above in case you are monitoring...

I have tried this with a few different denominators and it doesn't seem to be helping.  I would be curious to see if anyone could see what I am missing: my thumbnails are supposed to be coming from large images but render really small then are upsize...

Go to "Edit code" near the Customize button for the theme of the Online Shop.