Activate the New grub Configuration

Getting Started with Napatech Link-Virtualization™ Software
Platform
Napatech SmartNIC
Content Type
Getting Started Guide
Capture Software Version
Link-Virtualization™ Software 4.4

Procedure

Enter the following command to update grub and reboot the server. 
grub2-mkconfig -o /boot/grub2/grub.cfg
reboot