Theme is deleting the url's

I’m trying to add an external url in the Project url box (Projects widget), but everytime when the theme saves the change, it deletes the url.
Why does this happen?

Hey there,
I hope you’re doing well today

Are you using a parent theme or the child theme?
If you’re using the parent theme, try creating a child theme:
Child Theme Configurator – WordPress plugin | and test to see if the issue persists.

Best Regards,