Doug, looks like oxro.io is having issues. I just pushed out a Beta version of the plugin that should fix this. It uses your own server instead. You are welcome to give it a try. I did make a lot of changes in this newest version and it is still being tested. To get the beta version, go to the Account page inside the plugin, and look for the "Join the Beta program" check box. Then the update should show up.

You can add it to a reviewt template or a badge. For a review template look under the More Settings tab when editing a review template.

This should already be limited to jpg and png. Have you tested an svg file?

Try temporarily de-activing the cache plugin to see if that is indeed the issue.

https://search.google.com/test/rich-results

Might take some custom coding to pull the reviews from the database. You could turn on the schema for the review template. Google should be smart enough to read both schemas on the page.

Okay good. It seems to be working then. 

What happens if you click the "Download Reviews" button?

Click this and post and screenshot of the scrape details.

Can you post a screenshot of the scrape details so I can see the scrape id. Like so...

Also, what placeid did you use?