Problems running wordpress “staging” site.

Hi

I have set up a staging site which is a direct copy of my original site. They are both on two separate FTP’s. In the functions.php file on the copied version i put:

update_option(‘siteurl’,’https://example.com/blog’);
update_option(‘home’,’https://example.com/blog’);

Otherwise it would just throw me back to the URL of my original site and that kind of defies the point of having a “staging” site.

My problem is this. Everything i change in the back-end of the “copied” version changes in the “original” version as well despite the fact that i have modified the functions.php file. This leads me to think that the files i copied accross from the original site has settings that needs to be changed. I need to keep them seperate for development reasons.

I’m sorry if this is a bit unclear. Any questions i will try to answer to the best of my ability.

Any help is greatly appreciated

Thanks
Fred