Caret character inserted in VCS git commit dialog (Mac with External Keyboard)

When I open the Commit dialog using CMD-K and then press Option-I (Windows-I because I'm using a Windows external keyboard) to finalize the commit, I get a caret (ˆ) character inserted if my cursor is focused on the Commit Message field.  I've tested with two separate external keyboards and my mapping in the System Preferences Keyboard setting for this keyboard leaves Control the same, but swaps Cmd and Option keys. I'm running Mojave and IntelliJ 2018.2.  It also happens in DataGrip 2018.2 as well.

Any ideas on this?