R_HOME variable has been working for the past 5 years in my environments, this lets you know that I am not the average RStudio user. R_Home isn't the only broken variable because all the dynamic variables as I have found out are broken in 2022.12.0.
I noticed also that RStudio IDE has been compiled in a different way, I believe the new IDE version aka 2022.12.0 hasn't been tested at all, or if you prefeer, it has lots of legacy issues.
I noticed in several JSON files that those variables are present but IMHO have been compiled by not considering their purpose or meaning therefore custom use.
I believe that other Data Scientists will complain about this