Not able to change Default working directory

Hello everyone!
I am setting up an RStudio on MacBook and I'm trying to set up a default Working Directory. In general it is set to my user folder. I've created a folder named "R" within it and try to set it as default going to Tools -> Global Options -> Browse and choosing it. After that I get an error message "Error: Permission denied". I've given RStudio full disk access but still it does not allow me to set the default working directory. What can I try to do to fix it? Thank you!