grub install should only be performed when you know what you do. Especially when LUKS or any encryption is involved. Even on Ubuntu they don’t force grub to be installed automatically, as they had too many reports of broken systems. Sure the issue is given, but you need local access to the machine to perform it. To fully fix it, even the vendors have to ship new bios updates and such.
So if we know more about your partition-table we may be able to help you.