I have a main VL-7.2-STD distro on my laptop and a spare partition which I use to try different distros that pick my fancy.
Twice, on different distros that I have installed (Calculate Linux and Manjaro) I had a strange problem.
After running update-grub on my main VL distro, the newly installed distro had problems at booting, once systemd didn't couldn't load the kernel modules and another dracut was erased.
If I reinstalled the distro and did not run update-grub, and leave the old entry with the proper kernel name, it would work just fine.
Therefore, I deduce that the problem is with updating grub.
By the way, this did not happen if on the spare partition in installed VL, only with other distros.
Is there any issue with updating Grub which I should take into account?