Dear SyncFusion,
Thank you for the quick reply and screencasts!
Difference in my sample is that my checkbox was placed on the left inside the frozen columns.
Testing was done on a physical device (Samsung S4 mini running Android 4.4.4).
But now after some more testing it turns out that it has to with the INotifyPropertyChanged (INPC).
I didn't have it implemented, but your DataGridSample does have it.
Now all seems to work as it should.
Thanks again for the help and pointing me in the right direction!
Regards, Michel.