Windows User Environment Variables Not Loaded in Terminal

I use a corporate laptop, and have set my HOME variable to my Documents directory (for easier backup/restore) using the User Accounts -> "change my environment variables" (User Variables) dialog box. RStudio picks this up (Sys.getenv("HOME")) gives me C:\Users\MyName\Documents, but the Terminal pane does not (it returns C:\Users\MyName). This is mostly a problem because the RStudio GUI git commit operation complains that it cannot find my user.name configuration setting, which is in fact in the git --global config file under my HOME directory and git at the standard command line can access it.

Can I get MINGW to pick up the user environment variables? If not, where would I configure the environment variables for the RStudio Terminal?

> sessionInfo()
R version 3.6.3 (2020-02-29)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods  
[7] base     

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.7           magrittr_2.0.1       knitr_1.33          
 [4] hms_1.1.0            odbc_1.3.2           tidyselect_1.1.1    
 [7] bit_4.0.4            R6_2.5.0             rlang_0.4.11        
[10] fansi_0.5.0          blob_1.2.1           dplyr_1.0.7         
[13] tools_3.6.3          xfun_0.23            utf8_1.2.1          
[16] DBI_1.1.1            htmltools_0.5.1.1    ellipsis_0.3.2      
[19] assertthat_0.2.1     yaml_2.2.1           bit64_4.0.5         
[22] digest_0.6.27        tibble_3.1.2         lifecycle_1.0.0     
[25] crayon_1.4.1         dnvglsolardata_0.2.4 purrr_0.3.4         
[28] vctrs_0.3.8          bitops_1.0-7         RCurl_1.98-1.3      
[31] glue_1.4.2           evaluate_0.14        rmarkdown_2.9       
[34] pillar_1.6.1         compiler_3.6.3       generics_0.1.0      
[37] pkgconfig_2.0.3

Edit: I found Using the RStudio Terminal in the RStudio IDE – RStudio Support, and my setting is default (use Git Bash from Git for Windows) but when I independently start Git Bash the environment variables are inherited correctly. I also tried changing the Terminal to Command but the environment variables are still wrong when that setting takes effect.