I’m not sure if it’s worth going through this fix as well. I usually update pretty regularly. Here’s a summary of what I’ve already done.
Attempt 1
Following [HowTo] Solve Keyring Related Issues in Manjaro
sudo mv /etc/pacman.d/gnupg /etc/pacman.d/gnupg.bad
sudo pacman-key --init
sudo pacman-key --populate archlinux manjaro
sudo pacman -Sy gnupg archlinux-keyring manjaro-keyring
sudo pacman-key --refresh-keys
sudo pacman -Sc
Also checked the mirror was valid & refreshed mirrors.
Attempt 2
Following Pacman troubleshooting - Manjaro
sudo mv /etc/pacman.d/gnupg /etc/pacman.d/gnupg.bad2
cd ~/temp
curl -O https://mirror.easyname.at/manjaro/pool/overlay/manjaro-keyring-20230616-3-any.pkg.tar.xz
curl -O https://mirror.easyname.at/manjaro/pool/sync/archlinux-keyring-20230704-1-any.pkg.tar.zst
sudo pacman-key --init
sudo pacman -U manjaro-keyring*.pkg.tar.xz archlinux-keyring*.pkg.tar.zst
sudo pacman-key --populate archlinux manjaro
sudo pacman -Sc
sudo pacman-mirrors --geoid
Not sure if the last command helped but I think previously pacman-mirrors only showed one, now it shows two.