Hi Stephan,
Greetings from Syncfusion.
We were able to reproduce the issue Changing the zoom position, scrollsthe page to the top position and we confirm this as a bug and logged a defect report .You can keep track of the bug from the feedback portal below.
The fix will be available in our upcoming weekly patch release which is expected to be rolled out at July 16th, 2019.
If you have any more specification/precise replication procedure or a scenario to be tested, you can add it as a comment in the portal.
Thanks,
Kalai.