Rename in scope

I got a new computer and had to reinstall R and R studio. I'm not sure if the problem I am having is because of my computer, or the latest version of R/R studio, but Rename in Scope is no longer working for me the way it used to. I use this shortcut frequently within code chunks in R markdown. Occasionally I have had issues with it in the past, but restarting R Studio usually fixed the problem.

When I select a word to rename in scope, not all instances of that word are being highlighted in the code chunk. This feature is not behaving as it has in the past. What changed? How do I get it to work again?