The easiest way to correct the permissions issue is to remove the Guest account completely from the system. The guest account can be removed with the Garuda welcome utility, or via this command:
sudo pacman -R systemd-guest-user
After removing the guest account, reassign your user account UID & GID to 1000.
Power down completely, then restart. Do not login to your desktop session, instead switch to a TTY. Press CTRL+ALT+F3 to get to TTY3, then login as root (not your user account):
On the root account enter the following commands (you must substitute your username for "user"):
usermod -u 1000 user
groupmod -g 1000 user
After successfully reasigning the UID & GID, switch back to the login screen with CTRL+ALT+F1. Then login to your normal desktop user account.
Your GID & UID should both now be 1000, but it won't hurt to double check on everthing.
Check that the UID/GID and file ownerships for your user account has been reset properly:
ls -l /home/$USER
id -u ls -l /home/$USER
id -g ls -l /home/$USER
grep $USER /etc/passwd
grep $USER /etc/group