I was just on support chat for a while with Majid Hamdani. At the end of it, he asked me to do a plugin test and I agreed. However, that can't be done in this case.
I can't do a plugin test on the live site (cuz it's live) nor can I do it on the dev site.
The live site is set up as a verified site for Pinterest. In order to do a plugin test on the dev site I would have to disconnect the live site from Pinterest and go through the whole process of registering the dev site on Pinterest for business and then verifying the dev site. Then, I would have to undo all of that and reverify the live site with Pinterest.
I considered using my personal website as a test, but that won't work either because I would have to register my personal site on Pinterest for business, which would be silly.
My conclusion, therefore, is that I cannot do a plugin test for this issue.