Portfolio URL not working after page rename

Hi,

I have a portfolio page on my website. It was originally called My Projects, but I used the URL https://www.visualcinnamon.com/portfolio on buttons and such. However, I changed the name of the page to Projects. And then both https://www.visualcinnamon.com/portfolio and https://www.visualcinnamon.com/projects gave me error pages. I tried setting the portfolio page of the Theme Options to something else and then back to Projects, but that didn’t work. In the end I changed the title from the Projects page back to the original My Projects. Now https://www.visualcinnamon.com/my-projects does work, but https://www.visualcinnamon.com/portfolio still doesn’t (I again checked in the Theme Options that the My Projects page was labelled as the portfolio item)
Do you have any idea why this isn’t working?

Thank you!

Kind regards,

Nadieh