Category pages not working – page not found

[ Moderator note: moved to Fixing WordPress. ]

I created a new blog running the Twenty Seventeen theme. WordPress version 4.8. But the category pages are inaccessible. It shows the following error message:

OOPS! THAT PAGE CAN’T BE FOUND.

Here is a sample category page link: https://blog.praxiscenterforaesthetics.com/category/biennials-and-museums-to-know/

How can this issue be fixed? I did search around for a couple of days but didn’t find a solution.

I tried finding a workaround with plugins but it was not good enough.

Any help is appreciated. Thank you!