WP 5.2 update changed the format of my product url’s

After WP 5.2 upgrade all my page url’s have changed and now links from google, etc come up not found.

my url’s used to look like this

https://www.autobooks-aerobooks.com/product/twice-around-the-clock-the-yanks-at-le-mans/

Now they look like this

https://www.autobooks-aerobooks.com/?product=twice-around-the-clock-the-yanks-at-le-mans

where did the ? and the = come from? What can I do?

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