Hello, Jay545452
It is recommended to run import on a fresh WordPress installation. If you just do a new import over the old one, a mess in menus, media, and theme options will appear.
You can use the WordPress Database Reset plugin https://wordpress.org/plugins/wordpress-database-reset/ The plugin can be used to remove all the existing content, then you will be able to install the demo version from scratch.
Thanks for notices about the demo, in both cases, this option should be disabled – https://prnt.sc/82Qyl4qDfGlg
If you have any additional questions or concerns, please do not hesitate to reach out to us. Our support team is always available to assist you.
Kind Regards,
8theme team