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Perfect! I love it - well... at least I know exactly what the problem is. In fact, I ran into this myself and it seems to happen when somehow the report data is already cached. I will find a way to fix it. 

Can you be a little more specific? What isn't working - please try to provide as much details as possible so I can pin point any issue and promptly fix it.

It is normal that it asks for authentication every time - as a safety measure while it is in beta. Do you get any message back or nothing at all? If you check the browser console - do you see any error message?

Da Vinci Tools v2019.1.24 just came out and fixes the authentication flow problem.

Da Vinci Tools v2019.1.24 just came out with the fix

Looks like I broke something when I updated my website... will be fixed promptly.

I'm not able to reproduce this problem and DV doesn't do anything to the date picker besides adding new Date Range options in the drop-down list. Have you tried re-enabling Da Vinci and testing again? Maybe it was just a UX glitch resolved with a little refresh?