I've been using manjaro for a year and never ran into grub problems. However, Windows 10 asked to make a huge update and i let it, it restarted my notebook a few times (and you could see grub in each of those times) and when it was finally over and I tried to turn on the computer it booted directly to windows.
I searched solutions and it seemed that the uefi boot was to blame, so I followed the commands this post. I ended up in a grub-rescue screen, from there I followed these commands:
set prefix=(hd0,gpt6)/boot/grub insmod normal normal
Then grub reappeared and I was able to boot into manjaro (I haven't tried to boot into windows yet). But now every time I restart my notebook I end up in a grub rescue screen and have to run those lines again.
I'm not sure how to restore grub, I think that when I installed manjaro I used the Legacy Boot to avoid problems, but I'm not sure anymore because if I check windows boot mode it says UEFI. Could a huge update in windows 10 reset my boot configurations? What proceedings do I follow, BIOS or UEFI?
Can I instruct windows to boot from gpt6? Would this solve my problem?
And most importantly:
Is there a safe way to try this? I can't afford to lock myself away from my computer right now (and lose data would be really bad too, but I believe I can back up using the broken grub)
Useful information (I think?):
In grub-rescue screen if I run the ls command I end up with a list (i suppose that are the partitions):
ranging from gpt0 to gpt8, the one where insmod normal works is gpt6
Root and home are in separate partitions, if I remember correctly
grub rescue mode says "unknown file system" in restart, before the commands input
My Manjaro is KDE
I don't know much of computers, so please be patient.