dell lattitude 3510 boot breaks

I have a Dell Latitude 3510 machine where I just installed Arch Linux on it. My setup is as follows: grub2, luks of root partition. I followed official guides to setup. I was able to boot and use my laptop without any problem.and Now, after some time using it, when powering my laptop, the UEFI beeps and says that it has lost time setup and that no bootable partition is to be found. When I boot from arch ISO, I can come back to a normal boot process with a new grub-install, grub-mkconfig. It is the second time I have done it in a week. How can I investigate this problem ? I suspect that one problem is that the plug to my AC adapter is a bit loose and I may put my laptop in the position of a hard shutdown without any battery left. What happens to the grub setting ? Can I investigate the failure from the recovery ISO ? Some infos:

$ sudo fdisk -l
Disk /dev/nvme0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors
Disk model: BC511 NVMe SK hynix 512GB               
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 1234-####

Device           Start       End   Sectors  Size Type
/dev/nvme0n1p1    2048   2099199   2097152    1G EFI System
/dev/nvme0n1p2 2099200 840959999 838860800  400G Linux root (x86-64)


Disk /dev/mapper/root: 399.98 GiB, 429479952384 bytes, 838828032 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

$ grep -v '#' /etc/default/grub 

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX="cryptdevice=UUID=1234-####:root root=/dev/mapper/root"

GRUB_PRELOAD_MODULES="part_gpt part_msdos"
GRUB_TIMEOUT_STYLE=menu
GRUB_TERMINAL_INPUT=console
GRUB_GFXMODE=auto
GRUB_GFXPAYLOAD_LINUX=keep
GRUB_DISABLE_RECOVERY=true

$ grep -v '#' /etc/mkinitcpio.conf
MODULES=()

BINARIES=()

FILES=()

HOOKS=(base udev autodetect microcode modconf kms keyboard keymap consolefont block encrypt filesystems fsck)