outlook 2016 email reply problems

The outlook for mac support team has been very helpful and diligent with working with me on my problems. I am on MAC OS Sierra, Office 365 and my problem started 3 weeks ago whenever i reply to an email, the screen turns into a darker hue and window for the reply won't send unless i close the Outlook program / application. I am working on a MacBook air 2015 i7. I am now on the Fast Office Insider program where you get to use the new updates first but no solution seen so far. I understand that the engineers and CS people find my case to be the dreaded unicorn problem. I told them **** yeah, they should give me an iPad pro and and iPhone x! hahahahaha