I’ve been having problems with the app since yesterday. Yesterday and today I couldn’t open the app, but it got stuck even before the loading screen at the Shikudo logo.
The only way to fix this was to reinstall the app. I did this yesterday and today. But reinstalling apparently also comes with a bug: It seems to reset the values of the waterdrops rewards. I’m getting +3300 per session now, while I was getting about +20000 before that (I think).
I hope you can look into fixing these issues.