Hi,
Thanks for the bug report. The siteurl is obtained directly from wordpress so it should be correct. Also the plugin does a simple str_replace from your old url to your new url, so it’s very important you make sure you type the urls properly–it does not check for mistakes. Always include https:// as shown in the command line tool.
If you could give me an example of exactly what you are doing I can attempt to determine if there is a problem with the plugin.
Thanks.