Hi Siggi,
Sorry for the inconvenience.
We have checked with your query. In day view, view will be moved to next/previous day when one third (1/3) of the appointment is dragged to next/previous day. We are able to reproduce the issue “day view is not moved to next/previous day when one third of the appointment is dragged to next/previous day in some machines” in Xamarin Forms (UWP). But, view is moved to next/previous day when more than 60% of the appointment is dragged to next/previous view. We suspect that the issue is due to the different machine resolutions and we have logged bug report on this. We will fix this issue and include this fix in our upcoming Volume 2 SP1 release, which is expected to be available by end of month July 2018. We appreciate your patience until then.
Regards
Vigneshkumar R