After looking elsewhere, I found that the error was triggered by the erroneous “^” in the initrd string.
initrd /boot/intel-ucode.img /boot/initramfs-6.1-x86_64.img
works fine…
The error was self-induced, I’m sure, by the replacement of manjaro’s grub with a different distro’s bootloader. This is on a multi-boot system and demonstrates why it’s best not to install multiple linux distros on the same drive (imho, use a vm?), even though in this case the new linux installation, was on an external ssd.