The pane highlighting feature of the 1.4.1071-2 Preview ignores popped out source editor windows.
─ Session info ───────────────────────────────────────────────────────────────────────────────────────────────────────
setting value
version R version 4.0.2 (2020-06-22)
os macOS Catalina 10.15.7
system x86_64, darwin17.0
ui RStudio
language (EN)
collate en_US.UTF-8
ctype en_US.UTF-8
tz America/Denver
date 2020-12-03