Cannot rotate through open windows using Command + ~ using OSX High Sierra and 1.8.4

Tried latest hourly build (9/28), no luck.
Previously, in 1.8.3 and prior, and with all versions of OSX including High Sierra, one was able to rotate through all open windows using Command + ~ (including using the shift key to rotate in the 'opposite' order). As of 1.8.4 it only rotates through last two opened windows.
This is fine when one open window is the Monitor, thus ensuring the monitor window and its associated sketch are only rotated through, avoiding possible erroneous changes to other sketches. However, when monitor is not open, it only rotates through last two opened files. Is this a bug or an "improvement?" I suggest keeping the new functionality/logic when monitor open, but going back to previous functionality when monitor not open.

Start by reproducing the Command + ~ and Shift + Command + ~ window-rotation behavior in Arduino IDE 1.8.4 on macOS, comparing it with 1.8.3 and with the Monitor open or closed. Done means rotation matches the expected behavior in both cases without changing unrelated sketches.

Written by the indexing model from the issue text.