Thanks. No -- I used the latest stable release: Version 1.4.1106.
However, I fixed the problem by downloading the R4.1.0 Intel version -- it runs under Rosetta 2, the Mac Intel to Native M1 translator. I will update RStudio when the new version becomes available and then reload the native M1 Mac OS version of R. For my purposes, the temporary infelicities do not matter.
And I need to apologize for the noise -- more careful reading of the CRAN download page would have led me to the solution immediately.