While this happens the least of the quirks, it did happen a few times. Causes me to move my cursor back into the To field and delete the partial entry that I began typing before my cursor got moved. This includes backspacing and deleting characters as well. Here's a list of odd behavior I’ve experienced thus far:
This does not happen while using the web-based version of Outlook. When using the HubSpot Sales extension with the Outlook for Mac desktop app, there is quirky behavior.