Hi Alleja,
Thanks for reaching out to us.
If these websites are hosted on different servers, the issue may be related to the server configuration. Some hosting providers have security rules or server restrictions that can prevent certain extension packages from being uploaded or installed.
Please check whether there are any server-side security restrictions (such as a web application firewall, ModSecurity, or upload limits) that could be blocking the installation.
If possible, please let us know the exact error message Joomla displays when the installation fails, as this will help us identify the cause.
Best regards,