With grub 2.06.r456.g65bc45963-2 I reverted a change to also support installs with in-proper grub updates. Here the background:
A normal user will install grub only once. This happens when our installer Calamares does it for you. If you update the grub package via pamac or pacman you won’t update grub itself in your master boot record (MBR) or UEFI. This means you may still run an outdated grub on your system to boot your OS. Some grub updates however have security fixes which need to call grub-install. However, that most of you have different installs and there is now standard way like Asahi-LInux may do on their end calling grub-install is more riskier to break your bootability than not installing grub in your MBR.
Wait a minute, if I update grub I actually don’t? Yep, that is the case here. But why is it now a potential issue if the grub package gets updated? Well with a certain commit late 2022 the application fwsetup got a flag added to test for a function your UEFI firmware may or may not have. Those who have the support were fine, others not. Also the initial support called that application on legacy BIOS systems. That was fixed by upstream.
The background story of this can be found here: FS#75701 : grub 2:2.06.r322.gd9b4638c5-1 issue and here Re: [Regression] efi: Don't display a uefi-firmware entry if it's not su.
For me it is better to not call fwsetup at all and have a potential grub menu entry to enter the UEFI firmware from the grub menu, which potentially may fail in rare cases, than causing infinite bootloops into the UEFI firmware and not being able to boot Linux or any OS at all …
To be secure read our wiki on how to reinstall grub as needed: GRUB/Restore the GRUB Bootloader - Manjaro