Hi Manolo,
Thanks for contacting Syncfusion support.
We have tried to replicate the issue in your shared sample but unfortunately we cannot able to replicate the issue. We can able to return the value when we set the decimal values. We have also shared a simple video for your reference below.
If the issue still persists, then we suspect that you may missed to define the datatypes correctly, so please ensure your end you have defined the data type as string for Numeric Textbox value. Because of your Locale(“es-ES”) the decimal dot(.) takes comma(,) value and so we need to set the datatype as string.
Please check our shared information and if this information doesn’t meet your requirement or if we misunderstood your query, please get back to us with more information, so that it will help us to provide the solution at earliest.
Regards,
Arun P.