Site URL change affects Preview Mode

Hi, I’m new to wordpress and have encountered a problem.

Basically, my URL is https://www.juliekcohen.com
I set up my blog in a subfolder: https://www.juliecohen.com/blog
When I go into General settings and make the Site URL point to https://www.juliekcohen.com, my preview mode for any posts no longer works, and instead simply takes me to https://www.juliekcohen.com

Can you recommend how I can fix this?

Thanks,
Julie

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