Hi James,
Thank you for your interest in Syncfusion products.
You are hosting updown inside the CellEditTemplate. So updown will display when cell in edit mode.
Please change your code as below mentioned:
For more information. Please download the attached sample. Regarding your query about IsEnabled binding also possible in our UpDown control.
Please let us know if you have any questions.
Regards,
SudhaC.
DataGridDemo_2b48f4b4.zip