[Plugin: Redirection] random posts not working when install to sub-folder

Hi,
I just discovered that my redirects to a random post are not functioning – they used to and I’m not sure when they stopped working.

I have wordpress installed to a folder

i.e.
https://www.mysite.com/blog

when I put in redirect to random post
i.e. redirect https://www.mysite.com/blog/post1

the resulting url is
https://www.mysite.com/post2

i.e. it is correctly selecting a postname but not putting in the /blog/ subfolder under the root.

Any help would be greatly appreciated.

Thanks!