I have Dell Precision with windows 10 64bit installed on it. freeing some space and moving from
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
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.