Hi Helmut,
We have checked the reported issue by applying HeaderRowHeight to 0. Unfortunately, we couldn’t able to reproduce the issue with SfDataGrid version 18.4.0.47 and Xamarin forms version 4.5.0.617 in our end. We have checked by manually selection on first row and used SelectedIndex property to Select the first row. In both cases, the issue is not occurs. So, could you please share the below details to check the issue and provide a better solution asap.
i) In which platform your are facing the issue ?
ii) SfDataGrid complete configuration.
iii) Xamarin forms and SfDataGrid versions
Regards,
Karthik Raja