Unfortunately, double clicking the top of the window in MacOS doesn’t cause it maximize. The only way to maximize it is to press the green maximize button, however, that also puts the application in a separate workspace which is not what you might want.
I am running MacOS Monterey 12.0.1.
Hi! Yikes, I’ll be sure to file this bug report. However, as a workaround to maximize without opening a new workspace: hold option and go to the top right corner of Height (where you should see a diagonal 
) and double click.
Thanks for bringing this to our attention!
Hi! Circling back to tell you that the issue has been resolved. You should now be able to maximize in MacOS by double clicking in the header. Thanks again for the report 