Yes …, I see the problem
sudo nano /etc/default/grub
change this line at the bottom to false
GRUB_DISABLE_OS_PROBER=true
like this
GRUB_DISABLE_OS_PROBER=false
save the file by
ctrl + o then enter
to exit nano
ctrl + x
Then update grub
sudo grub-mkconfig -o /boot/grub/grub.cfg
Edit: Yes and then reboot as @manuel says!