R Studio Server keeps defaulting to old R binary even after I edited /etc/rstudio/rserver.conf

Question

I have two R executables on my server, 3.6 and 4.0. 3.6 lives in /usr/lib64/R/bin/R and R 4.0 lives in /opt/R/4.0.2/lib/R/bin/R.

Right now R Stu