I think you have not searched the forum about this, so you did not get the new info.
Garuda provides a pacman hook, to keep os-prober enabled by default, if it is not manually changed by the user.
Normally, you should not need to change anything and os-prober will run each time grub is auto-generated.
If you want to change this behavior, edit /etc/default/grub and change the relevant grub parameter to suite your preference.
Search the forum for the latest changes.