Ah, ok. I thought the entry was missing from the GRUB boot menu, which is how I got confused.
I think I can reproduce your issue here. Somehow your UEFI firmware isn’t picking up a Kicksecure boot entry, meaning the only option you have in your list is just the USB drive’s boot entry. Booting from that results in Kicksecure’s fallback bootloader being invoked, and due to a bug in Kicksecure this simply drops you to a GRUB shell.
To fix the problem, you should be able to use efibootmgr within Kicksecure to add a Kicksecure boot entry to the list that will work properly. Based on the screenshots you’ve sent, the proper command to do this should be:
sudo efibootmgr -c -d /dev/sda -p 1 -L 'Kicksecure' -l 'EFI\Kicksecure\shimx64.efi'
The other bug (where the fallback bootloader doesn’t work) needs to be solved and is something I’ll likely be looking into in the near future.