you opened the encrypted volume on /dev/sda2 with:
cryptsetup open /dev/sda2 tmp
and then mounted it with:
mount /dev/mapper/tmp /mnt
and then mounted the ESP with:
mount /dev/sda1 /mnt/boot/efi
and then you chrooted:
manjaro-chroot /mnt /bin/bash
or manjaro-chroot /mnt
(the /bin/bash is optional, you’ll get a sh-5.2 prompt without it, while you get a red root bash prompt with it)
You could adapt the title or create a new topic, with the relevant steps that you took as documented here, so that people will not have to go back here to see what was done.
In the first line It should be just tmp - not /tmp
(it is just a name which you refer to, not a path
I used “encrypted” im my example to avoid confusion, to be clear)
and it should be /dev/sda2 - not /dev/sdat
What is (still) the issue now?
As to your question - I just added to my previous reply.
It may be better to start a new topic.
I follow your advise and create a new topic. As for this issue, I will test whenever I overcome this grub problem and mark the solution here. I think we found the root cause for the mapping issue, i.e. a wrong hooks configuration.