I just found out that this behavior occures when the XHCI pre-boot mode is enabled in the BIOS. Disabling it solve the issue.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1069772 Title: Grub-EFI wont boot without a USB key 9 out 10 time To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1069772/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
