Suddenly the accordion stops working and when I try to look at the code in Chrome inspect (in case of 2 accordions) I can see the plugin is copying the content of the second accordion and includes it inside the first accordion. And in case of 1 accordion only it duplicate the content.
I had clear the cache and there is no cache plugin.
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This might be 3rd party plugin conflict. i can see there is unexpected wrapper
<li> before content area.
Please see the screenshot, i have attached our dev site accordion html and your site html screenshot
If you use any others plugin for accordion or included via theme please deactivate first and see whats happening.