My guess is that these two are similar: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/957277 and https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/969767 No GRUB menu (cause no other OS is detected), and whether Ubuntu or Windows boots is dependent on ones boot order.
My guess is that these two are similar: https:/ /bugs.launchpad .net/ubuntu/ +source/ grub2/+ bug/957277 and https:/ /bugs.launchpad .net/ubuntu/ +source/ ubiquity/ +bug/969767
No GRUB menu (cause no other OS is detected), and whether Ubuntu or Windows boots is dependent on ones boot order.