If you can respond to the questions and suggestions listed in my first reply to you, this would help us get a better idea of your situation and system so we can give you better feedback and suggestions to help you fix this please.
The issue is for both wifi and direct lan connection from dir865 to macbookpro.
Then i try disable dns relay and the internet connection resume. The next time when the internet connection drops, i enable dns relay. Seems to me that i need to toggle the dns relay to resume internet connection. Mine is a fibre connection from ISP to the dir865.