Hi Ralf,
Yes, I see this problem. The workaround for the time being would be to parse the Mask of each MaskedEditBox and trim the Text property value appropriately. I have attached a sample application that illustrates this workaround :
Sample_Application
The Mask used in this sample is PF:&&&&&. I have informed the Essential Tools development team regarding this issue and will update with their inputs on this one. We appreciate your feedback, and thanks for your patience.
Regards,
Guru Patwal
Syncfusion, Inc.