Interestingly, I went back to the JAMA website and was able to get it to import properly when following the sites citation button. I was using the add-on on my toolbar, could that be faulty with the new update???
(These issues would be either with your own installation or site-specific, so it's best to start new threads for new saving issues you're experiencing. I've moved this to a new thread.)
That page is saving authors properly for me via the Save to Zotero button. Is it still saving as a journal article for you, or is it saving as a webpage? If the latter, see Troubleshooting Translator Errors.
Upgrade Storage
https://jamanetwork-com.proxy.library.umkc.edu/journals/jamanetworkopen/fullarticle/2716997
That page is saving authors properly for me via the Save to Zotero button. Is it still saving as a journal article for you, or is it saving as a webpage? If the latter, see Troubleshooting Translator Errors.