In the current version of Rstudio, 1.3.1056, i seem to be having problems with the Assignment operator shortcut (Alt+"-"). This shortcut isn't working anymore using the "-" on the numeric keypad, but it still works fine using the "-" in the typing key group. Here's the session info.
R version 4.0.2 (2020-06-22)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)
Matrix products: default
 LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 LC_MONETARY=English_United States.1252 LC_NUMERIC=C
 LC_TIME=English_United States.1252