"Rename in Scope" is odd

As you may see, only one is marked in the rhs pic. Interestingly, in the same script, sometimes it works, sometimes not.

The last thing i did was to install rstudio addin package. Once I found it odd, and tried other scripts (no working), I removed the package and upgrade to the latest version or rstudio. Oops, still not working.
Thanks for advice.

I wasn't able to reproduce with the code snippets shown in your image. Can you post the full contents of a document wherein you're seeing this strange Rename in Scope behavior?