Try to chroot from the Garuda live USB into your installed Garuda system with the relevant tool or the following tutorial and reinstall and update GRUB
Then you should be able to use the Garuda GRUB, which will probe the other OS’s
Edit: First of all, welcome!
Second, before the method above, simply check with efibootmgr if you simply need to put Garuda entry as first with e.g.
sudo efibootmgr -o 0002,2001,2002,2003,0000
The sequence you can take from the first efibootmgr check and change as needed.