Hi Dmitriy,
Thanks for your feedback. This is a known shortcoming in the XPMenus framework in v3.2.1.0 and we have an open bug report defect# 259 on this :
Defect #259 - Keyboard navigation disabled in XPMenus
We will try our very best to address this issue at the earliest. We appreciate your feedback, and thanks for your patience.
Regards,
Guru Patwal
Syncfusion, Inc.