grub issue

[Michael ODonnell]

Hmmmm, semi-repeatable failures to boot all the way up to
a GUI-based login?

My first guess might be:

 - Maybe your graphics subsystem couldn't be initialized.

      Maybe your adapter has problems after a warm boot?

      Maybe driver not allowing enough time for initialization?

      Maybe compare output from "lsmod" for each case?

      See previous suggestions about /var/log/Xorg.0.log and friends.

Another (rather less probable) shot-in-the-dark guess:

 - Maybe GRUB is intermittently loading the wrong kernel or
   handing it the wrong commandline.

      Are we sure you're running the same kernel in both situations?

      Maybe compare output from "uname -a" and "cat /proc/cmdline"
      for each case?

I only mention that because the sort-of-cyclic nature you
described made me think it's just barely possible you're
enjoying some variant of this little bit of GRUB hell:

   https://duckduckgo.com/?q=GRUB_SAVEDEFAULT+GRUB_DEFAULT