Hi,
If it is working properly on other devices, it must be Key function issue on the Motorola. Please ensure that first.
If not, make sure you have configured the Key functions on your device:
motorola MC9190 -ITS Mobile RFID
Enter or function code is not working in the HTML Template screen
Mobile Devices and Browser - Wiki - SCN Wiki
Also, are you clicking on the buttons or using the shortcut keys?
Can you please post a snapshot?