I have Dell Precision with windows 10 64bit installed on it. freeing some space and moving from RAID to AHCI I was able to install Ubuntu 18.04.
sometimes on startup or restart the dual boot screen GNU grub 2.02 goes black for a fraction of a second and returns and after that everything freezes. the arrow key does not work and countdown stops.
the only solution is ctrl + alt + del to restart and most of the times after this restart the problem does not occur.
the only accessories is a wireless Logitech mouse-keyboard connected to USB. is it a common problem? searching the web saw many grub problems but mostly were receiving an error screen.
in this particular case, it seems that the problem was occurring because of the time system difference between windows and ubuntu.
I noticed whenever I shutdown or restart from windows the next start the problem was happening. the fast start on windows was off. also noticed whenever I use Ubuntu the next booting to windows cause windows to have not a correct time.
therefore I made Ubuntu to use local time
timedatectl set-local-rtc 1 --adjust-system-clock(which was an easier solution than making windows use UTC) and since then I have not faced the issue