So recently, I updated by RStudio version to the latest stable:
RStudio 2023.06.1+524 "Mountain Hydrangea" Release (547dcf861cac0253a8abb52c135e44e02ba407a1, 2023-07-07) for Windows.
Running Windows 11 with no such issue observed in the previous version of RStudio (2022.07.2-576).
When I have RStudio's Source Editor detached as a separate window, every time I "Run the current line or selection", either through the button on top of the window, or through the keyboard shortcut, the main window will resize. This makes it very difficult to maintain workflow and productivity.
I have captured a video to demonstrate the issue: RStudio automatically resize windows when Run current line or selection - YouTube
Anyone with the same issue?