Grub Rescue while rebooting (manjaro dual boot)

you chrooted then from chroot you reinstalled grub and updated grub (see you still getting cryptic still don’t know what you did EXACTLY)?

I really doubt you did properly what the instructions told you. I may be mistaken but a GRUB reinstall, to me, would be the proper step to fix your issue.

Anyway here is starting point How to provide good information