After installing version 1.8 There was a problem QApage
How to solve the problem
It's working on my test site with the same theme. I think the error is related to custom HTML that you have on the page, because it thinks the "upvoteCount" property is under "QAPage" rather than "Question".
According to the validator your HTML is invalid, so I would check that and make sure you fix those div/span tags.
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April 20, 2021: Q2A 1.8.6 released!